JVM IR: fix containing declaration for top level members in wrapped descriptors

In addition to fixing getContainingDeclaration, change origin of
multifile facades to FILE_CLASS since the corresponding class descriptor
should also be skipped when computing containing declaration. This fixes
the problem with internal function calls in -Xmultifile-parts-inherit
mode (previously we incorrectly mangled the function name in
MethodSignatureMapper), and also fixes coroutine intrinsic calls when
compiling kotlin-stdlib with JVM IR. In the latter case, all intrinsics
(such as isBuiltInSuspendCoroutineUninterceptedOrReturn) are present in
sources, and were previously not detected as intrinsics by the code in
`generateInlineIntrinsic` because the FQ name didn't match: it had an
additional component for the file class name.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/MethodSignatureMapper.kt

@@ -39,7 +39,6 @@ import org.jetbrains.kotlin.load.java.getOverriddenBuiltinReflectingJvmDescripto
 import org.jetbrains.kotlin.load.kotlin.TypeMappingMode
 import org.jetbrains.kotlin.load.kotlin.forceSingleValueParameterBoxing
 import org.jetbrains.kotlin.load.kotlin.getJvmModuleNameForDeserializedDescriptor
-import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodGenericSignature
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodParameterKind
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmMethodSignature
@@ -105,7 +104,7 @@ class MethodSignatureMapper(private val context: JvmBackendContext) {
 
         if (function.isTopLevel) {
             if (Visibilities.isPrivate(function.visibility) && newName != "<clinit>" &&
-                function.parentAsClass.attributeOwnerId in context.multifileFacadeForPart
+                (function.parent as? IrClass)?.attributeOwnerId in context.multifileFacadeForPart
             ) {
                 return "$newName$${function.parentAsClass.name.asString()}"
             }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/GenerateMultifileFacades.kt

@@ -129,6 +129,7 @@ private fun generateMultifileFacades(
         }.apply {
             parent = file
             createImplicitParameterDeclarationWithWrappedDescriptor()
+            origin = IrDeclarationOrigin.FILE_CLASS
             if (jvmClassName.packageFqName != kotlinPackageFqName) {
                 context.classNameOverride[this] = jvmClassName
             }

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/WrappedDescriptors.kt

@@ -12,7 +12,6 @@ import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.descriptors.IrBasedDeclarationDescriptor
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.toKotlinType
@@ -1056,11 +1055,12 @@ open class WrappedFieldDescriptor(
 
 private fun getContainingDeclaration(declaration: IrDeclarationWithName): DeclarationDescriptor {
     val parent = declaration.parent
-    return if (parent is IrClass && parent.origin == IrDeclarationOrigin.FILE_CLASS && parent.parent is IrExternalPackageFragment) {
-        // JVM IR adds facade classes for IR of functions/properties loaded from dependencies. However, these shouldn't exist
-        // in the descriptor hierarchy, since this is what the old backend (dealing with descriptors) expects.
-        return (parent.parent as IrExternalPackageFragment).packageFragmentDescriptor
+    val parentDescriptor = (parent as IrSymbolOwner).symbol.descriptor
+    return if (parent is IrClass && parent.origin == IrDeclarationOrigin.FILE_CLASS) {
+        // JVM IR adds facade classes for IR of functions/properties loaded both from sources and dependencies. However, these shouldn't
+        // exist in the descriptor hierarchy, since this is what the old backend (dealing with descriptors) expects.
+        parentDescriptor.containingDeclaration!!
     } else {
-        (parent as IrSymbolOwner).symbol.descriptor
+        parentDescriptor
     }
 }

compiler/testData/codegen/box/multifileClasses/optimized/internalFunction.kt

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM
+// IGNORE_LIGHT_ANALYSIS
+// WITH_RUNTIME
+// !INHERIT_MULTIFILE_PARTS
+
+// FILE: test.kt
+
+@file:JvmMultifileClass
+@file:JvmName("Test")
+
+internal fun <T> List<T>.first(): T = get(0)
+
+fun test(): String {
+    return listOf("OK").first()
+}
+
+// FILE: box.kt
+
+fun box(): String = test()

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -16517,6 +16517,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/calls.kt");
             }
 
+            @TestMetadata("internalFunction.kt")
+            public void testInternalFunction() throws Exception {
+                runTest("compiler/testData/codegen/box/multifileClasses/optimized/internalFunction.kt");
+            }
+
             @TestMetadata("overlappingFuns.kt")
             public void testOverlappingFuns() throws Exception {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/overlappingFuns.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -16517,6 +16517,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/calls.kt");
             }
 
+            @TestMetadata("internalFunction.kt")
+            public void testInternalFunction() throws Exception {
+                runTest("compiler/testData/codegen/box/multifileClasses/optimized/internalFunction.kt");
+            }
+
             @TestMetadata("overlappingFuns.kt")
             public void testOverlappingFuns() throws Exception {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/overlappingFuns.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -15392,6 +15392,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/calls.kt");
             }
 
+            @TestMetadata("internalFunction.kt")
+            public void testInternalFunction() throws Exception {
+                runTest("compiler/testData/codegen/box/multifileClasses/optimized/internalFunction.kt");
+            }
+
             @TestMetadata("overlappingFuns.kt")
             public void testOverlappingFuns() throws Exception {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/overlappingFuns.kt");