[FIR] Replace single supertype scope with list of scopes of supertypes in use site scopes

This big refactoring is needed to cleanup building of overrides
  mappings and prevent creating redundant intersection overrides in
  cases when there is no need in them:

```kotlin
interface A {
    fun foo()
}

interface B {
    fun foo()
}

interface C : A, B {
    override fun foo()
}
```

Before this refactoring there was next override tree:
C.foo
  intersection override (A.foo, B.foo)
    A.foo
    B.foo

Also this commit fixes special mapping of overrides in jvm scopes
  for declarations which have kotlin builtins in supertypes with
  special java mapping rules (collections, for example)

compiler/testData/codegen/box/collections/irrelevantImplCharSequence.kt

@@ -1,5 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
-// FIR status: wrong ABSTRACT_MEMBER_NOT_IMPLEMENTED, probably provoked by override mapping error
 // TARGET_BACKEND: JVM
 
 // FILE: J.java

compiler/testData/codegen/box/collections/irrelevantImplMutableListSubstitution.kt

@@ -1,5 +1,5 @@
 // IGNORE_BACKEND_FIR: JVM_IR
-// FIR status: wrong ABSTRACT_MEMBER_NOT_IMPLEMENTED, probably provoked by override mapping error
+// FIR status: wrong CONFLICTING_INHERITED_JVM_DECLARATIONS, probably provoked by override mapping error
 // TARGET_BACKEND: JVM
 
 // FILE: J.java

compiler/testData/diagnostics/tests/j+k/collectionOverrides/collectionStringImpl.fir.kt

@@ -1,85 +0,0 @@
-// FILE: CollectionStringImpl.java
-
-import java.util.Collection;
-import java.util.Iterator;
-
-public class CollectionStringImpl implements Collection<String> {
-    @Override
-    public int size() {
-        return 0;
-    }
-
-    @Override
-    public boolean isEmpty() {
-        return false;
-    }
-
-    @Override
-    public boolean contains(Object o) {
-        return false;
-    }
-
-
-    @Override
-    public Iterator<String> iterator() {
-        return null;
-    }
-
-
-    @Override
-    public Object[] toArray() {
-        return new Object[0];
-    }
-
-
-    @Override
-    public <T> T[] toArray(T[] a) {
-        return null;
-    }
-
-    @Override
-    public boolean add(String s) {
-        return false;
-    }
-
-    @Override
-    public boolean remove(Object o) {
-        return false;
-    }
-
-    @Override
-    public boolean containsAll(Collection<?> c) {
-        return false;
-    }
-
-    @Override
-    public boolean addAll(Collection<? extends String> c) {
-        return false;
-    }
-
-    @Override
-    public boolean removeAll(Collection<?> c) {
-        return false;
-    }
-
-    @Override
-    public boolean retainAll(Collection<?> c) {
-        return false;
-    }
-
-    @Override
-    public void clear() {
-
-    }
-
-    public boolean contains(String o) {
-        return true;
-    }
-}
-
-// FILE: main.kt
-
-fun test(x: CollectionStringImpl) {
-    x.<!OVERLOAD_RESOLUTION_AMBIGUITY!>contains<!>("")
-    (x as Collection<String>).contains("")
-}

compiler/testData/diagnostics/tests/j+k/collectionOverrides/collectionStringImpl.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: CollectionStringImpl.java
 
 import java.util.Collection;

compiler/testData/diagnostics/tests/j+k/collectionOverrides/containsAndOverload.fir.kt

@@ -12,10 +12,10 @@ abstract class KA : A() {
 }
 
 fun foo(a: A, ka: KA) {
-    a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>contains<!>("")
-    a.<!NONE_APPLICABLE!>contains<!>(1)
-    "" <!OVERLOAD_RESOLUTION_AMBIGUITY!>in<!> a
-    1 <!NONE_APPLICABLE!>in<!> a
+    a.contains("")
+    a.contains(<!ARGUMENT_TYPE_MISMATCH!>1<!>)
+    "" in a
+    <!ARGUMENT_TYPE_MISMATCH!>1<!> in a
 
     ka.contains("")
     ka.contains(<!ARGUMENT_TYPE_MISMATCH!>1<!>)

compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplCharSequence.fir.kt

@@ -1,25 +0,0 @@
-// FILE: AImpl.java
-
-abstract public class AImpl {
-    public char charAt(int index) {
-        return '1';
-    }
-
-    public final int length() { return 1; }
-}
-
-// FILE: A.java
-public class A extends AImpl implements CharSequence {
-    public CharSequence subSequence(int start, int end) {
-        return null;
-    }
-}
-
-// FILE: X.kt
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class X<!> : A()
-
-fun main() {
-    val x = X()
-    x[0]
-    x.length
-}

compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplCharSequence.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: AImpl.java
 
 abstract public class AImpl {

compiler/testData/diagnostics/tests/override/FakeOverrideModality3.fir.kt

@@ -0,0 +1,16 @@
+interface A {
+    fun foo() {}
+}
+
+interface B : A {
+    abstract override fun foo()
+}
+
+interface C : A {
+    abstract override fun foo()
+}
+
+interface D : A
+
+// Fake override Z#foo should be abstract
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class Z<!> : B, C, D

compiler/testData/diagnostics/tests/override/FakeOverrideModality3.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 interface A {
     fun foo() {}
 }

compiler/testData/diagnostics/tests/scopes/kt1822.fir.kt

@@ -10,7 +10,7 @@ interface T {
 }
 
 class G : C(), T {
-    override fun foo() {} //should be an error "cannot infer visibility"; for now 'public' is inferred in such cases
+    override fun <!CANNOT_CHANGE_ACCESS_PRIVILEGE!>foo<!>() {} //should be an error "cannot infer visibility"; for now 'public' is inferred in such cases
 }
 
 open class A {

compiler/testData/diagnostics/testsWithStdLib/annotations/jvmDefault/javaOverride.fir.kt

@@ -0,0 +1,72 @@
+// !JVM_DEFAULT_MODE: enable
+// !JVM_TARGET: 1.8
+
+// FILE: JavaInterface.java
+public interface JavaInterface {
+    default void test() {}
+
+    default void testForNonDefault() {}
+
+    void testAbstract();
+}
+
+// FILE: 1.kt
+
+interface KotlinInterface : JavaInterface {
+    @<!DEPRECATION!>JvmDefault<!>
+    override fun test() {}
+
+    <!NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT!>override fun testForNonDefault()<!> {}
+
+    override fun testAbstract() {}
+}
+
+interface KotlinInterface2 : JavaInterface, KotlinInterface {
+    @<!DEPRECATION!>JvmDefault<!>
+    override fun test() {}
+
+    <!NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT!>override fun testForNonDefault()<!> {}
+
+    override fun testAbstract() {}
+}
+
+
+interface KotlinInterfaceForIndirect : JavaInterface {
+
+}
+
+interface KotlinInterfaceIndirectInheritance : KotlinInterfaceForIndirect {
+
+    @<!DEPRECATION!>JvmDefault<!>
+    override fun test() {}
+
+    <!NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT!>override fun testForNonDefault()<!> {}
+
+    override fun testAbstract() {}
+}
+
+open class KotlinClass : JavaInterface {
+    override fun test() {}
+
+    override fun testForNonDefault() {}
+
+    override fun testAbstract() {}
+}
+
+interface KotlinInterfaceX  {
+
+    fun test() {}
+
+    fun testForNonDefault() {}
+
+    fun testAbstract() {}
+}
+
+interface KotlinInterfaceManySuper: JavaInterface, KotlinInterfaceX {
+    @<!DEPRECATION!>JvmDefault<!>
+    override fun test() {}
+
+    <!NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT!>override fun testForNonDefault()<!> {}
+
+    override fun testAbstract() {}
+}

compiler/testData/diagnostics/testsWithStdLib/annotations/jvmDefault/javaOverride.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // !JVM_DEFAULT_MODE: enable
 // !JVM_TARGET: 1.8
 

compiler/testData/ir/irText/classes/kt45853.fir.ir.txt

@@ -0,0 +1,61 @@
+FILE fqName:<root> fileName:/kt45853.kt
+  CLASS CLASS name:A modality:ABSTRACT visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
+    CONSTRUCTOR visibility:public <> () returnType:<root>.A [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:ABSTRACT visibility:public superTypes:[kotlin.Any]'
+    PROPERTY name:a visibility:public modality:ABSTRACT [val]
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-a> visibility:public modality:ABSTRACT <> ($this:<root>.A) returnType:<root>.A?
+        correspondingProperty: PROPERTY name:a visibility:public modality:ABSTRACT [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  CLASS CLASS name:B modality:FINAL visibility:public superTypes:[<root>.AX]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.B
+    CONSTRUCTOR visibility:public <> () returnType:<root>.B [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.AX'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:B modality:FINAL visibility:public superTypes:[<root>.AX]'
+    FUN name:getA visibility:public modality:FINAL <> ($this:<root>.B) returnType:<root>.X?
+      overridden:
+        public abstract fun getA (): @[FlexibleNullability] <root>.X? [fake_override] declared in <root>.AX
+      $this: VALUE_PARAMETER name:<this> type:<root>.B
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun getA (): <root>.X? declared in <root>.B'
+          CALL 'public open fun <get-a> (): @[FlexibleNullability] <root>.AX? declared in <root>.AX' superQualifier='CLASS IR_EXTERNAL_JAVA_DECLARATION_STUB CLASS name:AX modality:ABSTRACT visibility:public superTypes:[<root>.A; <root>.X]' type=@[FlexibleNullability] <root>.AX? origin=GET_PROPERTY
+            $this: GET_VAR '<this>: <root>.B declared in <root>.B.getA' type=<root>.B origin=null
+    PROPERTY FAKE_OVERRIDE name:a visibility:public modality:OPEN [fake_override,val]
+      overridden:
+        public open a: @[FlexibleNullability] <root>.AX? [val]
+      FUN FAKE_OVERRIDE name:<get-a> visibility:public modality:OPEN <> ($this:<root>.AX) returnType:@[FlexibleNullability] <root>.AX? [fake_override]
+        annotations:
+          Override
+        correspondingProperty: PROPERTY FAKE_OVERRIDE name:a visibility:public modality:OPEN [fake_override,val]
+        overridden:
+          public open fun <get-a> (): @[FlexibleNullability] <root>.AX? declared in <root>.AX
+        $this: VALUE_PARAMETER name:<this> type:<root>.AX
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [fake_override,operator] declared in <root>.AX
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int [fake_override] declared in <root>.AX
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String [fake_override] declared in <root>.AX
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any

compiler/testData/ir/irText/classes/kt45853.kt

@@ -1,5 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_FIR: JVM_IR
 // SKIP_KT_DUMP
 // DUMP_EXTERNAL_CLASS: X
 // DUMP_EXTERNAL_CLASS: AX
@@ -9,8 +8,6 @@ abstract class A {
     abstract val a: A?
 }
 
-//Fir doesn't treat B.getA as an override, because it is not return-type compatible with AX.getA
-// Which might be correct behaivour. So disable fir till KT-46042
 class B() : AX() {
     override fun getA(): X? = super.a
 }

compiler/testData/ir/irText/firProblems/DelegationAndInheritanceFromJava.fir.ir.txt

@@ -9,6 +9,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:add visibility:public modality:OPEN <> ($this:<root>.Impl, element:@[FlexibleNullability] kotlin.String?) returnType:kotlin.Boolean
       overridden:
         public abstract fun add (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun add (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:element index:0 type:@[FlexibleNullability] kotlin.String?
       BLOCK_BODY
@@ -20,6 +21,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:addAll visibility:public modality:OPEN <> ($this:<root>.Impl, elements:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>) returnType:kotlin.Boolean
       overridden:
         public abstract fun addAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun addAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:elements index:0 type:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>
       BLOCK_BODY
@@ -31,6 +33,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:clear visibility:public modality:OPEN <> ($this:<root>.Impl) returnType:kotlin.Unit
       overridden:
         public abstract fun clear (): kotlin.Unit [fake_override] declared in <root>.Foo.A
+        public abstract fun clear (): kotlin.Unit [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       BLOCK_BODY
         CALL 'public abstract fun clear (): kotlin.Unit [fake_override] declared in <root>.Foo.B' type=kotlin.Unit origin=null
@@ -39,6 +42,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:iterator visibility:public modality:OPEN <> ($this:<root>.Impl) returnType:kotlin.collections.MutableIterator<@[FlexibleNullability] kotlin.String?> [operator]
       overridden:
         public abstract fun iterator (): kotlin.collections.MutableIterator<@[FlexibleNullability] kotlin.String?> [fake_override,operator] declared in <root>.Foo.A
+        public abstract fun iterator (): kotlin.collections.MutableIterator<@[FlexibleNullability] kotlin.String?> [fake_override,operator] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun iterator (): kotlin.collections.MutableIterator<@[FlexibleNullability] kotlin.String?> [operator] declared in <root>.Impl'
@@ -48,6 +52,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:remove visibility:public modality:OPEN <> ($this:<root>.Impl, element:@[FlexibleNullability] kotlin.String?) returnType:kotlin.Boolean
       overridden:
         public abstract fun remove (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun remove (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:element index:0 type:@[FlexibleNullability] kotlin.String?
       BLOCK_BODY
@@ -59,6 +64,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:removeAll visibility:public modality:OPEN <> ($this:<root>.Impl, elements:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>) returnType:kotlin.Boolean
       overridden:
         public abstract fun removeAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun removeAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:elements index:0 type:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>
       BLOCK_BODY
@@ -70,6 +76,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:retainAll visibility:public modality:OPEN <> ($this:<root>.Impl, elements:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>) returnType:kotlin.Boolean
       overridden:
         public abstract fun retainAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun retainAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:elements index:0 type:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>
       BLOCK_BODY
@@ -81,6 +88,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:contains visibility:public modality:OPEN <> ($this:<root>.Impl, element:@[FlexibleNullability] kotlin.String?) returnType:kotlin.Boolean [operator]
       overridden:
         public abstract fun contains (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override,operator] declared in <root>.Foo.A
+        public abstract fun contains (element: @[FlexibleNullability] kotlin.String?): kotlin.Boolean [fake_override,operator] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:element index:0 type:@[FlexibleNullability] kotlin.String?
       BLOCK_BODY
@@ -92,6 +100,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:containsAll visibility:public modality:OPEN <> ($this:<root>.Impl, elements:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>) returnType:kotlin.Boolean
       overridden:
         public abstract fun containsAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun containsAll (elements: kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       VALUE_PARAMETER name:elements index:0 type:kotlin.collections.Collection<@[FlexibleNullability] kotlin.String?>
       BLOCK_BODY
@@ -103,6 +112,7 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     FUN DELEGATED_MEMBER name:isEmpty visibility:public modality:OPEN <> ($this:<root>.Impl) returnType:kotlin.Boolean
       overridden:
         public abstract fun isEmpty (): kotlin.Boolean [fake_override] declared in <root>.Foo.A
+        public abstract fun isEmpty (): kotlin.Boolean [fake_override] declared in <root>.Foo.B
       $this: VALUE_PARAMETER name:<this> type:<root>.Impl
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun isEmpty (): kotlin.Boolean declared in <root>.Impl'
@@ -112,10 +122,12 @@ FILE fqName:<root> fileName:/DelegationAndInheritanceFromJava.kt
     PROPERTY DELEGATED_MEMBER name:size visibility:public modality:OPEN [val]
       overridden:
         public abstract size: kotlin.Int [fake_override,val]
+        public abstract size: kotlin.Int [fake_override,val]
       FUN DELEGATED_MEMBER name:<get-size> visibility:public modality:OPEN <> ($this:<root>.Impl) returnType:kotlin.Int
         correspondingProperty: PROPERTY DELEGATED_MEMBER name:size visibility:public modality:OPEN [val]
         overridden:
           public abstract fun <get-size> (): kotlin.Int [fake_override] declared in <root>.Foo.A
+          public abstract fun <get-size> (): kotlin.Int [fake_override] declared in <root>.Foo.B
         $this: VALUE_PARAMETER name:<this> type:<root>.Impl
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-size> (): kotlin.Int declared in <root>.Impl'

compiler/testData/ir/irText/firProblems/ImplicitReceiverStack.fir.ir.txt

@@ -154,6 +154,7 @@ FILE fqName:<root> fileName:/ImplicitReceiverStack.kt
     FUN name:iterator visibility:public modality:FINAL <> ($this:<root>.PersistentImplicitReceiverStack) returnType:kotlin.collections.Iterator<<root>.ImplicitReceiverValue<*>> [operator]
       overridden:
         public abstract fun iterator (): kotlin.collections.Iterator<<root>.ImplicitReceiverValue<*>> [fake_override,operator] declared in <root>.ImplicitReceiverStack
+        public abstract fun iterator (): kotlin.collections.Iterator<T of kotlin.collections.Iterable> [operator] declared in kotlin.collections.Iterable
       $this: VALUE_PARAMETER name:<this> type:<root>.PersistentImplicitReceiverStack
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public final fun iterator (): kotlin.collections.Iterator<<root>.ImplicitReceiverValue<*>> [operator] declared in <root>.PersistentImplicitReceiverStack'

compiler/testData/ir/irText/firProblems/MultiList.fir.ir.txt

@@ -378,9 +378,9 @@ FILE fqName:<root> fileName:/MultiList.kt
         public open fun sort (p0: @[FlexibleNullability] java.util.Comparator<in @[FlexibleNullability] E of java.util.ArrayList?>?): kotlin.Unit declared in java.util.ArrayList
       $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<E of java.util.ArrayList>
       VALUE_PARAMETER name:p0 index:0 type:@[FlexibleNullability] java.util.Comparator<in @[FlexibleNullability] <root>.Some<T of <root>.SomeList>?>?
-    FUN FAKE_OVERRIDE name:removeAt visibility:public modality:OPEN <> ($this:java.util.ArrayList<E of java.util.ArrayList>, p0:kotlin.Int) returnType:@[EnhancedNullability] <root>.Some<T of <root>.SomeList> [fake_override]
+    FUN FAKE_OVERRIDE name:removeAt visibility:public modality:OPEN <> ($this:java.util.ArrayList<E of java.util.ArrayList>, p0:kotlin.Int) returnType:@[EnhancedNullability] <root>.Some<T of <root>.SomeList> [fake_override,operator]
       overridden:
-        public open fun removeAt (p0: kotlin.Int): @[EnhancedNullability] E of java.util.ArrayList declared in java.util.ArrayList
+        public open fun removeAt (p0: kotlin.Int): @[EnhancedNullability] E of java.util.ArrayList [operator] declared in java.util.ArrayList
       $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<E of java.util.ArrayList>
       VALUE_PARAMETER name:p0 index:0 type:kotlin.Int
   CLASS CLASS name:FinalList modality:FINAL visibility:public superTypes:[<root>.SomeList<kotlin.String>]
@@ -572,8 +572,8 @@ FILE fqName:<root> fileName:/MultiList.kt
         public open fun sort (p0: @[FlexibleNullability] java.util.Comparator<in @[FlexibleNullability] <root>.Some<T of <root>.SomeList>?>?): kotlin.Unit [fake_override] declared in <root>.SomeList
       $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<E of java.util.ArrayList>
       VALUE_PARAMETER name:p0 index:0 type:@[FlexibleNullability] java.util.Comparator<in @[FlexibleNullability] <root>.Some<kotlin.String>?>?
-    FUN FAKE_OVERRIDE name:removeAt visibility:public modality:OPEN <> ($this:java.util.ArrayList<E of java.util.ArrayList>, p0:kotlin.Int) returnType:@[EnhancedNullability] <root>.Some<kotlin.String> [fake_override]
+    FUN FAKE_OVERRIDE name:removeAt visibility:public modality:OPEN <> ($this:java.util.ArrayList<E of java.util.ArrayList>, p0:kotlin.Int) returnType:@[EnhancedNullability] <root>.Some<kotlin.String> [fake_override,operator]
       overridden:
-        public open fun removeAt (p0: kotlin.Int): @[EnhancedNullability] <root>.Some<T of <root>.SomeList> [fake_override] declared in <root>.SomeList
+        public open fun removeAt (p0: kotlin.Int): @[EnhancedNullability] <root>.Some<T of <root>.SomeList> [fake_override,operator] declared in <root>.SomeList
       $this: VALUE_PARAMETER name:<this> type:java.util.ArrayList<E of java.util.ArrayList>
       VALUE_PARAMETER name:p0 index:0 type:kotlin.Int