add tests for serializaion of nested classes and objects (builtins and js)

compiler/tests/org/jetbrains/kotlin/serialization/builtins/BuiltInsSerializerTest.kt

@@ -64,6 +64,10 @@ public class BuiltInsSerializerTest : TestCaseWithTmpdir() {
         doTest("simple.kt")
     }
 
+    fun testNestedClassesAndObjects() {
+        doTest("nestedClassesAndObjects.kt")
+    }
+
     fun testCompileTimeConstants() {
         doTest("compileTimeConstants.kt")
     }

compiler/tests/org/jetbrains/kotlin/serialization/js/KotlinJavascriptSerializerTest.kt

@@ -101,6 +101,10 @@ public class KotlinJavascriptSerializerTest : TestCaseWithTmpdir() {
         doTest("builtinsSerializer/simple.kt")
     }
 
+    fun testNestedClassesAndObjects() {
+        doTest("builtinsSerializer/nestedClassesAndObjects.kt")
+    }
+
     fun testCompileTimeConstants() {
         doTest("builtinsSerializer/compileTimeConstants.kt")
     }