[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/callableReference/function/getArityViaFunctionImpl.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // TODO: muted automatically, investigate should it be ran for JS or not
 // IGNORE_BACKEND: JS, NATIVE

compiler/testData/codegen/box/callableReference/function/local/closureWithSideEffect.kt

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

compiler/testData/codegen/box/callableReference/function/local/equalsHashCode.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS, JS_IR
 
 fun box(): String {

compiler/testData/codegen/box/callableReference/function/local/extension.kt

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

compiler/testData/codegen/box/callableReference/function/local/extensionToLocalClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     class A
     fun A.foo() = "OK"

compiler/testData/codegen/box/callableReference/function/local/extensionToPrimitive.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     fun Int.is42With(that: Int) = this + 2 * that == 42
     return if ((Int::is42With)(16, 13)) "OK" else "Fail"

compiler/testData/codegen/box/callableReference/function/local/extensionWithClosure.kt

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

compiler/testData/codegen/box/callableReference/function/local/localLocal.kt

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

compiler/testData/codegen/box/callableReference/function/local/recursiveClosure.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun foo(until: Int): String {
     fun bar(x: Int): String =
         if (x == until) "OK" else bar(x + 1)

compiler/testData/codegen/box/callableReference/function/local/simple.kt

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

compiler/testData/codegen/box/callableReference/function/local/simpleClosure.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 fun box(): String {
     val result = "OK"
 

compiler/testData/codegen/box/callableReference/function/local/simpleWithArg.kt

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

compiler/testData/codegen/box/callableReference/function/local/unitWithSideEffect.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 var state = 23
 
 fun box(): String {