FIR: Fix serialization of non-delegated members in FirDelegatedMemberScope

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirDelegatedMemberScope.kt

@@ -33,7 +33,7 @@ class FirDelegatedMemberScope(
     private val containingClass: FirClass,
     private val declaredMemberScope: FirScope,
     private val delegateFields: List<FirField>,
-) : FirScope() {
+) : FirScope(), FirContainingNamesAwareScope {
     private val dispatchReceiverType = containingClass.defaultType()
     private val overrideChecker = FirStandardOverrideChecker(session)
 
@@ -171,6 +171,31 @@ class FirDelegatedMemberScope(
             result += delegatedSymbol
         }
     }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    private val callableNamesLazy: Set<Name> by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        buildSet {
+            addAll(declaredMemberScope.getContainingCallableNamesIfPresent())
+
+            delegateFields.flatMapTo(this) {
+                buildScope(it)?.getCallableNames() ?: emptySet()
+            }
+        }
+    }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    private val classifierNamesLazy: Set<Name> by lazy(LazyThreadSafetyMode.PUBLICATION) {
+        buildSet {
+            addAll(declaredMemberScope.getContainingClassifierNamesIfPresent())
+
+            delegateFields.flatMapTo(this) {
+                buildScope(it)?.getClassifierNames() ?: emptySet()
+            }
+        }
+    }
+
+    override fun getCallableNames(): Set<Name> = callableNamesLazy
+    override fun getClassifierNames(): Set<Name> = classifierNamesLazy
 }
 
 private object MultipleDelegatesWithTheSameSignatureKey : FirDeclarationDataKey()

compiler/testData/codegen/box/delegation/differentModules.kt

@@ -14,15 +14,16 @@ interface UClass : PsiClass {
 
 abstract class BaseKotlinUClass(
     psi: PsiClass,
+    val w: String,
 ) : UClass, PsiClass by psi
 
 // MODULE: main(base)
 // FILE: main.kt
 
-class A(psi: PsiClass) : BaseKotlinUClass(psi)
+class A(psi: PsiClass) : BaseKotlinUClass(psi, "K")
 
-fun bar(uClass: UClass): String = uClass.foo()!!
+fun bar(uClass: UClass): String = uClass.foo()!! + (uClass as BaseKotlinUClass).w
 
 fun box(): String = bar(A(object : PsiClass {
-    override fun foo(): String? = "OK"
+    override fun foo(): String? = "O"
 }))