Fix this remapping in inner class constructors

Inner class constructors should use the argument instead of reading
outer `this` from a field because if such an access happens before a
delegating constructor call, e.g. when evaluating an argument, a JVM
bytecode validation error will be thrown. (The only operation on `this`
allowed before a delegating constructor call is SETFIELD, and only if
the field in question is declared in the same class.)

compiler/testData/codegen/box/classes/inheritedInnerClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 class Outer() {
   open inner class InnerBase() {
   }

compiler/testData/codegen/box/classes/inner/kt6708.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 open class A() {
     open inner class InnerA
 }
@@ -10,4 +9,4 @@ class B : A() {
 fun box(): String {
     B().InnerB()
     return "OK"
-}
+}

compiler/testData/codegen/box/classes/propertyInInitializer.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 class Outer() {
   val s = "xyzzy"