JVM_IR: collect free type parameters when serializing FIR metadata

The "free" in "createFreeFakeLambdaDescriptor" and such refers to the
fact that there are no references to type parameters from outside the
current declaration. This is necessary because at the point where the
metadata is written, the type parameters may not even be in scope (e.g.
local delegated properties are serialized at class level, but may refer
to function-scope type parameters).

compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirMetadataSerializer.kt

@@ -44,61 +44,79 @@ class FirMetadataSerializer(
         }
     }
 
-    private fun FirTypeRef.approximated(toSuper: Boolean): FirTypeRef {
+    private fun FirTypeRef.approximated(toSuper: Boolean, typeParameterSet: MutableCollection<FirTypeParameter>): FirTypeRef {
         val approximatedType = if (toSuper)
             approximator.approximateToSuperType(coneType, TypeApproximatorConfiguration.PublicDeclaration)
         else
             approximator.approximateToSubType(coneType, TypeApproximatorConfiguration.PublicDeclaration)
-        return withReplacedConeType(approximatedType as? ConeKotlinType)
+        return withReplacedConeType(approximatedType as? ConeKotlinType).apply { coneType.collectTypeParameters(typeParameterSet) }
+    }
+
+    private fun ConeKotlinType.collectTypeParameters(c: MutableCollection<FirTypeParameter>) {
+        when (this) {
+            is ConeFlexibleType -> {
+                lowerBound.collectTypeParameters(c)
+                upperBound.collectTypeParameters(c)
+            }
+            is ConeClassLikeType ->
+                for (projection in type.typeArguments) {
+                    if (projection is ConeKotlinTypeProjection) {
+                        projection.type.collectTypeParameters(c)
+                    }
+                }
+            is ConeTypeParameterType -> c.add(lookupTag.typeParameterSymbol.fir)
+            else -> Unit
+        }
     }
 
     private fun FirFunction<*>.copyToFreeAnonymousFunction(): FirAnonymousFunction {
         val function = this
         return buildAnonymousFunction {
+            val typeParameterSet = function.typeParameters.filterIsInstanceTo(mutableSetOf<FirTypeParameter>())
             session = function.session
             origin = FirDeclarationOrigin.Source
             symbol = FirAnonymousFunctionSymbol()
-            returnTypeRef = function.returnTypeRef.approximated(toSuper = true)
+            returnTypeRef = function.returnTypeRef.approximated(toSuper = true, typeParameterSet)
-            receiverTypeRef = function.receiverTypeRef?.approximated(toSuper = false)
+            receiverTypeRef = function.receiverTypeRef?.approximated(toSuper = false, typeParameterSet)
             isLambda = (function as? FirAnonymousFunction)?.isLambda == true
             valueParameters.addAll(function.valueParameters.map {
                 buildValueParameterCopy(it) {
-                    returnTypeRef = it.returnTypeRef.approximated(toSuper = false)
+                    returnTypeRef = it.returnTypeRef.approximated(toSuper = false, typeParameterSet)
                 }
             })
-            // TODO need containers' type parameters too
+            typeParameters += typeParameterSet
-            function.typeParameters.filterIsInstanceTo(typeParameters)
         }
     }
 
     private fun FirPropertyAccessor.copyToFreeAccessor(): FirPropertyAccessor {
         val accessor = this
         return buildPropertyAccessor {
+            val typeParameterSet = accessor.typeParameters.toMutableSet()
             session = accessor.session
             origin = FirDeclarationOrigin.Source
-            returnTypeRef = accessor.returnTypeRef.approximated(toSuper = true)
+            returnTypeRef = accessor.returnTypeRef.approximated(toSuper = true, typeParameterSet)
             symbol = FirPropertyAccessorSymbol()
             isGetter = accessor.isGetter
             status = accessor.status
             accessor.valueParameters.mapTo(valueParameters) {
                 buildValueParameterCopy(it) {
-                    returnTypeRef = it.returnTypeRef.approximated(toSuper = false)
+                    returnTypeRef = it.returnTypeRef.approximated(toSuper = false, typeParameterSet)
                 }
             }
             annotations += accessor.annotations
-            // TODO need containers' type parameters too
+            typeParameters += typeParameterSet
-            typeParameters += accessor.typeParameters
         }
     }
 
     private fun FirProperty.copyToFreeProperty(): FirProperty {
         val property = this
         return buildProperty {
+            val typeParameterSet = property.typeParameters.toMutableSet()
             session = property.session
             origin = FirDeclarationOrigin.Source
             symbol = FirPropertySymbol(property.symbol.callableId)
-            returnTypeRef = property.returnTypeRef.approximated(toSuper = true)
+            returnTypeRef = property.returnTypeRef.approximated(toSuper = true, typeParameterSet)
-            receiverTypeRef = property.receiverTypeRef?.approximated(toSuper = false)
+            receiverTypeRef = property.receiverTypeRef?.approximated(toSuper = false, typeParameterSet)
             name = property.name
             initializer = property.initializer
             delegate = property.delegate
@@ -111,8 +129,7 @@ class FirMetadataSerializer(
             isLocal = property.isLocal
             status = property.status
             annotations += property.annotations
-            // TODO need containers' type parameters too
+            typeParameters += typeParameterSet
-            typeParameters += property.typeParameters
         }.apply {
             delegateFieldSymbol?.fir = this
         }

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

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/properties/localDelegated/variableOfGenericType.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // WITH_REFLECT