Fix serialization of type parameters inner generic class

The call to `createTopLevel` instead of `create` (which creates
serializers for outer classes properly, with correct type parameter
contexts) caused MetadataSerializer to write type parameter metadata
incorrectly.  For example, in the following case:

    class A<E> {
        inner class B<T, E> { ... }
    }

A's type parameter E would get id 0, and B's type parameters T and E
would get ids 0 and 1. This is a problem because ids are supposed to be
unique for each class including its outer classes, and deserializer,
decompiler and stub builder rely on this assumption.

JVM metadata is unaffected because `create` is called correctly there,
see MemberCodegen#generateKotlinClassMetadataAnnotation

 #KT-24944 Fixed

compiler/cli/src/org/jetbrains/kotlin/cli/metadata/MetadataSerializer.kt

@@ -158,7 +158,7 @@ open class MetadataSerializer(private val dependOnOldBuiltIns: Boolean) {
         }
 
         private fun serializeClass(classDescriptor: ClassDescriptor) {
-            val classProto = DescriptorSerializer.createTopLevel(extension).classProto(classDescriptor).build()
+            val classProto = DescriptorSerializer.create(classDescriptor, extension).classProto(classDescriptor).build()
             proto.addClass_(classProto)
 
             serializeClasses(classDescriptor.unsubstitutedInnerClassesScope.getContributedDescriptors(DescriptorKindFilter.CLASSIFIERS))