IR KT-50039 don't initialize outer 'this' in delegating constructor

compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerDefaultArgument.kt

@@ -10,3 +10,8 @@ class A {
 }
 
 fun box() = A().box()
+
+// CHECK_BYTECODE_TEXT
+// 1 PUTFIELD A\$Inner\.this\$0 : LA;
+//  ^ A$Inner.this$0 SHOULD be written in primary constructor of A$Inner,
+//    and SHOULD NOT be written in corresponding default arguments stub.