[FIR2IR] Introduce staged transformation (first step)

Now FE IR -> BE IR transformation is performed in multiple stages
controller by Fir2IrConverter. Stages are
 * files & classes registration
 * supertypes & type parameters handling
 * functions & properties signature generation
 * body generation

After each step we have guarantee (with exception of local classes &
type inference combination, and external symbols) that required symbols
(class/function/property/variable/type parameter)
are already bound to real declarations and have correct parents.

This commit also fixes incorrect parents for local classes

compiler/testData/codegen/box/functions/localFunctions/callInlineLocalInLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/captureUpperBoundedTypeParameter.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun <T, V : T> f(x: V): V {
     fun g(y: V) = y
     return g(x)

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambdaInnerUsage1.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambdaInnerUsage2.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/kt2895.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun outer() {
     fun inner(i: Int) {
         if (i > 0){

compiler/testData/codegen/box/functions/localFunctions/kt3308.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     fun <T> foo(t: T) = t
 

compiler/testData/codegen/box/functions/localFunctions/kt3978.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box() : String {
     fun local(i: Int = 1) : Int {
         return i

compiler/testData/codegen/box/functions/localFunctions/kt3978_2.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 class C() {
     fun box(): Int {
         fun local(i: Int = 1): Int {

compiler/testData/codegen/box/functions/localFunctions/kt4119.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun foo(f: (Int?) -> Int): Int {
     return f(0)
 }

compiler/testData/codegen/box/functions/localFunctions/kt4119_2.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     infix fun Int.foo(a: Int): Int = a + 2
 

compiler/testData/codegen/box/functions/localFunctions/kt4514.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     fun String.f() = this
     val vf: String.() -> String = { this }

compiler/testData/codegen/box/functions/localFunctions/kt4783.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 class T(val value: Int) {
 }
 

compiler/testData/codegen/box/functions/localFunctions/kt4989.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 class It(val id: String)
 
 fun box(): String {

compiler/testData/codegen/box/functions/localFunctions/localFunctionVsLocalVariable.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     var s = ""
     var foo = "O"

compiler/testData/codegen/box/functions/localFunctions/nameClash.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 
 fun test(b: Boolean): String {
     if (b) {

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunWithoutClosure.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     fun foo(x: String) = x
     fun foo() = foo("K")

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunction.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     var s = ""
 

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunction1.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     var s = ""
     var foo = "K"

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunction2.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     var s = ""
     var foo = "K"

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunction3.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     var s = ""
     var foo = "O"

compiler/testData/codegen/box/functions/localFunctions/parameterAsDefaultValue.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun foo(): String {
     fun bar(x: String, y: String = x): String {
         return y