Fix algorithm of determining modality for fake overrides

Previously we inferred "open" if there was at least one open member in the
hierarchy. However, that's not correct when that member is overridden by
another member in the hierarchy which is abstract. This led to incorrect code
being accepted by the front-end, and an exception during the bridge generation

 #KT-12467 Fixed

compiler/testData/diagnostics/tests/override/FakeOverrideModality1.kt

@@ -0,0 +1,14 @@
+interface A {
+    fun foo() {}
+}
+
+interface B : A {
+    abstract override fun foo()
+}
+
+interface C {
+    abstract fun foo()
+}
+
+// Fake override Z#foo should be abstract
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Z<!> : B, C

compiler/testData/diagnostics/tests/override/FakeOverrideModality1.txt

@@ -0,0 +1,30 @@
+package
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface B : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Z : B, C {
+    public constructor Z()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/override/FakeOverrideModality2.kt

@@ -0,0 +1,18 @@
+interface A {
+    fun foo() {}
+}
+
+interface B : A {
+    abstract override fun foo()
+}
+
+interface C : A {
+    abstract override fun foo()
+}
+
+interface D : A {
+    override fun foo() = super.foo()
+}
+
+// Fake override Z#foo should be open
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class Z<!> : B, C, D

compiler/testData/diagnostics/tests/override/FakeOverrideModality2.txt

@@ -0,0 +1,37 @@
+package
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface B : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface D : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Z : B, C, D {
+    public constructor Z()
+    public open override /*3*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*3*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*3*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*3*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/override/FakeOverrideModality3.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
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Z<!> : B, C, D

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

@@ -0,0 +1,37 @@
+package
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface B : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*1*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface D : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Z : B, C, D {
+    public constructor Z()
+    public open override /*3*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*3*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*3*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*3*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/override/kt12358.kt

@@ -6,4 +6,4 @@ interface B
 
 abstract class C : A(), B
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Test<!> : C()
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class Test<!> : C()

compiler/testData/diagnostics/tests/override/kt12358.txt

@@ -17,12 +17,12 @@ public abstract class C : A, B {
     public constructor C()
     public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
-    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+    public abstract override /*2*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
 public final class Test : C {
     public constructor Test()
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
-    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public abstract override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

compiler/testData/diagnostics/tests/override/kt12467.kt

@@ -0,0 +1,14 @@
+interface A {
+    fun test() {
+    }
+}
+
+interface B : A {
+    override fun test()
+}
+
+interface C : A
+
+interface D : C, B
+
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class K<!> : D

compiler/testData/diagnostics/tests/override/kt12467.txt

@@ -0,0 +1,37 @@
+package
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface B : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C : A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface D : C, B {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*2*/ /*fake_override*/ fun test(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class K : D {
+    public constructor K()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}