[FIR] Fix computing labels of anonymous functions (not lambdas)

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/BaseConverter.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.fir.types.builder.buildImplicitTypeRef
 import org.jetbrains.kotlin.lexer.KtToken
 import org.jetbrains.kotlin.lexer.KtTokens.*
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.stubs.elements.KtFunctionElementType
 import kotlin.contracts.ExperimentalContracts
 
 abstract class BaseConverter(
@@ -54,6 +55,9 @@ abstract class BaseConverter(
     }
 
     override fun LighterASTNode.getLabelName(): String? {
+        if (tokenType == KtNodeTypes.FUN) {
+            return getParent()?.getLabelName()
+        }
         this.forEachChildren {
             when (it.tokenType) {
                 KtNodeTypes.LABEL_QUALIFIER -> return it.asText.replaceFirst("@", "")

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/DeclarationsConverter.kt

@@ -1327,7 +1327,8 @@ class DeclarationsConverter(
         val isLocal = !(parentNode?.tokenType == KT_FILE || parentNode?.tokenType == CLASS_BODY)
         val target: FirFunctionTarget
         val functionBuilder = if (identifier == null && isLocal) {
-            target = FirFunctionTarget(labelName = functionDeclaration.getLabelName(), isLambda = false)
+            val labelName = functionDeclaration.getLabelName() ?: context.calleeNamesForLambda.lastOrNull()?.identifier
+            target = FirFunctionTarget(labelName = labelName, isLambda = false)
             FirAnonymousFunctionBuilder().apply {
                 source = functionDeclaration.toFirSourceElement()
                 receiverTypeRef = receiverType

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -99,7 +99,11 @@ open class RawFirBuilder(
     }
 
     override fun PsiElement.getLabelName(): String? {
-        return (this as? KtExpressionWithLabel)?.getLabelName()
+        return when (this) {
+            is KtExpressionWithLabel -> getLabelName()
+            is KtNamedFunction -> parent.getLabelName()
+            else -> null
+        }
     }
 
     override fun PsiElement.getExpressionInParentheses(): PsiElement? {
@@ -967,7 +971,7 @@ open class RawFirBuilder(
                     receiverTypeRef = receiverType
                     symbol = FirAnonymousFunctionSymbol()
                     isLambda = false
-                    labelName = function.getLabelName()
+                    labelName = function.getLabelName() ?: context.calleeNamesForLambda.lastOrNull()?.identifier
                 }
             } else {
                 FirSimpleFunctionBuilder().apply {

compiler/fir/raw-fir/psi2fir/testData/rawBuilder/expressions/lambdaAndAnonymousFunction.txt

@@ -14,7 +14,7 @@ FILE: lambdaAndAnonymousFunction.kt
     }
     public? final? fun test_2(): R|kotlin/Unit| {
         run#(fun <anonymous>(): Int <inline=Unknown>  {
-            ^ IntegerLiteral(1)
+            ^@run IntegerLiteral(1)
         }
         )
     }

compiler/fir/raw-fir/psi2fir/testData/rawBuilder/expressions/locals.txt

@@ -31,7 +31,7 @@ FILE: locals.kt
         }
         .foo#()
         ^withLocals sum#(code#, Local#(IntegerLiteral(1)).diff#(), fun <anonymous>(x: Int, y: Int): <implicit> <inline=Unknown>  {
-            ^ x#.plus#(y#)
+            ^@sum x#.plus#(y#)
         }
         )
     }

compiler/testData/codegen/box/functions/localReturnInsideFunctionExpression.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun simple() = fun (): Boolean { return true }
 
 fun withLabel() = l@ fun (): Boolean { return@l true }
@@ -8,4 +7,4 @@ fun box(): String {
     if (!withLabel()()) return "Test withLabel failed"
 
     return "OK"
-}
+}