[FIR2IR]: fix translation of this references in instance methods

Currently FirThisReceiverExpression of instance methods are translated
to references of the class' thisReceiver,
not the method's dispatch receiver,
which causes problems with IrFrameMap::typeOf,
as the class' thisReceiver is not in the typeMap.

This commit translates non-qualified "this" references of
instance methods to references of the methods' dispatch receiver.

compiler/testData/codegen/box/dataClasses/changingVarParam.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(var string: String)
 
 fun box(): String {

compiler/testData/codegen/box/dataClasses/equals/alreadyDeclared.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Int) {
   override fun equals(other: Any?): Boolean = false
 }

compiler/testData/codegen/box/dataClasses/equals/null.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val v: Any?)
 
 data class B<T>(val v: T)

compiler/testData/codegen/box/dataClasses/equals/nullother.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 class Dummy {
   override fun equals(other: Any?) = true
 }

compiler/testData/codegen/box/dataClasses/equals/sameinstance.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val arg: Any? = null)
 
 fun box() : String {

compiler/testData/codegen/box/dataClasses/hashCode/alreadyDeclared.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Int) {
   override fun hashCode(): Int = -3
 }

compiler/testData/codegen/box/dataClasses/hashCode/null.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val a: Any?, var x: Int)
 data class B(val a: Any?)
 data class C(val a: Int, var x: Int?)

compiler/testData/codegen/box/dataClasses/mixedParams.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(var x: Int, val z: Int)
 
 fun box(): String {

compiler/testData/codegen/box/dataClasses/multiDeclaration.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Int, val y: Any?, val z: String)
 
 fun box(): String {

compiler/testData/codegen/box/dataClasses/nonTrivialFinalMemberInSuperClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 abstract class Base {
     final override fun toString() = "OK"
     final override fun hashCode() = 42

compiler/testData/codegen/box/dataClasses/toString/alreadyDeclared.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Int) {
   override fun toString(): String = "!"
 }

compiler/testData/codegen/box/dataClasses/twoValParams.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Int, val y: String)
 
 fun box(): String {

compiler/testData/codegen/box/dataClasses/unitComponent.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 data class A(val x: Unit)
 
 fun box(): String {