[FIR Serialization] Fix serialization of generated nested classifiers

^KT-55759 Fixed

plugins/kotlinx-serialization/testData/boxIr/generatedClassifiersViaLibraryDependency.kt

@@ -0,0 +1,23 @@
+// ISSUE: KT-55759
+// TARGET_BACKEND: JVM_IR
+// WITH_STDLIB
+
+// MODULE: lib
+// TARGET_PLATFORM: JVM
+// FILE: lib.kt
+
+import kotlinx.serialization.*
+
+@Serializable
+class Test
+
+// MODULE: jvm(lib)()()
+// TARGET_PLATFORM: JVM
+// FILE: main.kt
+
+import kotlinx.serialization.*
+import kotlinx.serialization.descriptors.*
+
+fun box(): String {
+    return if (Test.serializer().descriptor.toString() == "Test()") "OK" else "FAIL"
+}

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirBlackBoxTestGenerated.java

@@ -69,6 +69,12 @@ public class SerializationFirBlackBoxTestGenerated extends AbstractSerialization
             runTest("plugins/kotlinx-serialization/testData/boxIr/externalSerialierJava.kt");
         }
 
+        @Test
+        @TestMetadata("generatedClassifiersViaLibraryDependency.kt")
+        public void testGeneratedClassifiersViaLibraryDependency() throws Exception {
+            runTest("plugins/kotlinx-serialization/testData/boxIr/generatedClassifiersViaLibraryDependency.kt");
+        }
+
         @Test
         @TestMetadata("genericBaseClassMultiple.kt")
         public void testGenericBaseClassMultiple() throws Exception {

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationIrBoxTestGenerated.java

@@ -67,6 +67,12 @@ public class SerializationIrBoxTestGenerated extends AbstractSerializationIrBoxT
         runTest("plugins/kotlinx-serialization/testData/boxIr/externalSerialierJava.kt");
     }
 
+    @Test
+    @TestMetadata("generatedClassifiersViaLibraryDependency.kt")
+    public void testGeneratedClassifiersViaLibraryDependency() throws Exception {
+        runTest("plugins/kotlinx-serialization/testData/boxIr/generatedClassifiersViaLibraryDependency.kt");
+    }
+
     @Test
     @TestMetadata("genericBaseClassMultiple.kt")
     public void testGenericBaseClassMultiple() throws Exception {