K2: Don't report BUILDER_INFERENCE_STUB_RECEIVER for members of Any

This commit actually does two things:
- Adds Any scope to stub type
- Makes CheckDispatchReceiver treat stub types
as non-null for the unsafe call check to make such candidates viable

Related to KT-59369

compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/ScopeUtils.kt

@@ -91,7 +91,25 @@ private fun ConeKotlinType.scope(
             intersectionType.scope(useSiteSession, scopeSession, requiredMembersPhase) ?: FirTypeScope.Empty
         }
     }
-
+    is ConeStubTypeForChainInference -> {
+        // Actually, it should be the intersection of bounds, but K1 doesn't think so.
+        // interface ABC {
+        //     fun foo()
+        // }
+        //
+        // class Buildee<out U : ABC> {
+        //     fun get(): U = null!!
+        // }
+        //
+        // fun <F: ABC> buildsome(l: Buildee<F>.() -> Unit) {}
+        //
+        // fun test() {
+        //    buildsome {
+        //        this.get().foo()
+        //    }
+        // }
+        useSiteSession.builtinTypes.anyType.type.scope(useSiteSession, scopeSession, requiredMembersPhase)
+    }
     is ConeRawType -> lowerBound.scope(useSiteSession, scopeSession, requiredMembersPhase)
     is ConeDynamicType -> useSiteSession.dynamicMembersStorage.getDynamicScopeFor(scopeSession)
     is ConeFlexibleType -> lowerBound.scope(useSiteSession, scopeSession, requiredMembersPhase)

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ResolutionStages.kt

@@ -184,7 +184,15 @@ object CheckDispatchReceiver : ResolutionStage() {
         }
 
         val dispatchReceiverValueType = candidate.dispatchReceiver?.resolvedType ?: return
-        val isReceiverNullable = !AbstractNullabilityChecker.isSubtypeOfAny(context.session.typeContext, dispatchReceiverValueType)
+
+        // TODO: Actually, we should treat stub types as non-nullable for the isReceiverNullable check
+        // Otherwise, we won't able to resolve to member toString/hashCode due to UnsafeCall error
+        // It was possible in K1, due to the fact that K1 doesn't use AbstractNullabilityChecker directly
+        // But, AbstractNullabilityChecker.isSubtypeOfAny doesn't respect stubTypeEqualToAnything
+        val isStubType = dispatchReceiverValueType is ConeStubTypeForChainInference
+        val isReceiverNullable =
+            !AbstractNullabilityChecker.isSubtypeOfAny(context.session.typeContext, dispatchReceiverValueType) && !isStubType
+
 
         val isCandidateFromUnstableSmartcast =
             (candidate.originScope as? FirUnstableSmartcastTypeScope)?.isSymbolFromUnstableSmartcast(candidate.symbol) == true

compiler/testData/diagnostics/tests/inference/builderInference/stubTypes/memberScope.fir.kt

@@ -23,10 +23,10 @@ fun test() {
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test2()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get().test2()<!>
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.hashCode()<!>
+        get()?.hashCode()
-        get()?.<!NONE_APPLICABLE!>equals<!>(1)
+        get()?.equals(1)
         // there is `String?.equals` extension
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get().equals("")<!>
+        get().equals("")
     }
     val ret2 = build {
         emit(1)
@@ -34,12 +34,12 @@ fun test() {
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test2()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get().test2()<!>
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.hashCode()<!>
+        get()?.hashCode()
-        get()?.<!NONE_APPLICABLE!>equals<!>(1)
+        get()?.equals(1)
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x?.hashCode()<!>
+        x?.hashCode()
-        x?.<!NONE_APPLICABLE!>equals<!>(1)
+        x?.equals(1)
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x.equals("")<!>
+        x.equals("")
     }
     val ret3 = build {
         emit(1)
@@ -47,11 +47,11 @@ fun test() {
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test2()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get().test2()<!>
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.hashCode()<!>
+        get()?.hashCode()
-        get()?.<!NONE_APPLICABLE!>equals<!>(1)
+        get()?.equals(1)
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x?.hashCode()<!>
+        x?.hashCode()
-        x?.<!NONE_APPLICABLE!>equals<!>(1)
+        x?.equals(1)
 
         if (get() == null) {}
         if (<!FORBIDDEN_IDENTITY_EQUALS_WARNING!>get() === null<!>) {}
@@ -163,11 +163,11 @@ fun test() {
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test2()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get().test2()<!>
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.hashCode()<!>
+        get()?.hashCode()
-        get()?.<!NONE_APPLICABLE!>equals<!>(1)
+        get()?.equals(1)
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x?.hashCode()<!>
+        x?.hashCode()
-        x?.<!NONE_APPLICABLE!>equals<!>(1)
+        x?.equals(1)
 
         if (get() == null) {}
         if (<!FORBIDDEN_IDENTITY_EQUALS_WARNING!>get() === null<!>) {}
@@ -293,11 +293,11 @@ fun test() {
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.test2()<!>
         <!BUILDER_INFERENCE_STUB_RECEIVER!>get().test2()<!>
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()?.hashCode()<!>
+        get()?.hashCode()
-        get()?.<!NONE_APPLICABLE!>equals<!>(1)
+        get()?.equals(1)
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x?.hashCode()<!>
+        x?.hashCode()
-        x?.<!NONE_APPLICABLE!>equals<!>(1)
+        x?.equals(1)
 
         if (get() == null) {}
         if (<!FORBIDDEN_IDENTITY_EQUALS_WARNING!>get() === null<!>) {}

compiler/testData/diagnostics/tests/inference/builderInference/stubTypes/nullability.fir.kt

@@ -25,27 +25,27 @@ fun <R1 : R2, R2> build4(x: R2, block: TestInterface<R1>.() -> Unit): R1 = TODO(
 fun test(a: String?) {
     val ret1 = build {
         emit(1)
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         x <!USELESS_ELVIS!>?: 1<!>
         x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
         ""
     }
     val ret2 = build2 {
         emit(1)
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         x <!USELESS_ELVIS!>?: 1<!>
         x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
         ""
     }
     val ret3 = build3 {
         emit(1)
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        get()<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         val x = get()
-        <!BUILDER_INFERENCE_STUB_RECEIVER!>x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")<!>
+        x<!UNNECESSARY_SAFE_CALL!>?.<!>equals("")
         x <!USELESS_ELVIS!>?: 1<!>
         x<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
         ""

compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/kt36220.fir.kt

@@ -1,19 +0,0 @@
-// !OPT_IN: kotlin.RequiresOptIn
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-
-import kotlin.experimental.ExperimentalTypeInference
-
-class TypeDefinition<KotlinType : Any> {
-    fun parse(parser: (serializedValue: String) -> KotlinType?): Unit = TODO()
-    fun serialize(parser: (value: KotlinType) -> Any?): Unit = TODO()
-}
-
-@OptIn(ExperimentalTypeInference::class)
-fun <KotlinType : Any> defineType(definition: TypeDefinition<KotlinType>.() -> Unit): Unit = TODO()
-
-fun main() {
-    defineType {
-        parse { it.toInt() }
-        serialize { <!BUILDER_INFERENCE_STUB_RECEIVER!>it.toString()<!> }
-    }
-}

compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/kt36220.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !OPT_IN: kotlin.RequiresOptIn
 // !DIAGNOSTICS: -UNUSED_PARAMETER