Test infra: refactor IGNORE_BACKEND directive

treat it as a general one, introduce *_K1 and *_K2 variants for
more specific ignoring

compiler/testData/ir/interpreter/instanceOf.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND_K1: JVM_IR
 interface Base
 
 @CompileTimeCalculation

compiler/testData/ir/interpreter/jvm/classReference.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND_K1: JVM_IR
 package test
 
 import kotlin.reflect.KFunction

compiler/testData/ir/interpreter/jvm/parameterReference.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND_K1: JVM_IR
 package test
 
 import kotlin.reflect.KFunction

compiler/testData/ir/irText/classes/clashingFakeOverrideSignatures.kt

@@ -1,6 +1,6 @@
 // SKIP_KLIB_TEST
 // See KT-44312
-// IGNORE_BACKEND_FIR: ANY
+// IGNORE_BACKEND_K2: ANY
 //  ^ TODO decide if we want to fix KT-42020 for FIR as well
 
 open class Base<T> {

compiler/testData/ir/irText/declarations/multiplatform/expectClassInherited.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !LANGUAGE: +MultiPlatformProjects
 
 expect abstract class A protected constructor() {

compiler/testData/ir/irText/declarations/multiplatform/expectedSealedClass.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !LANGUAGE: +MultiPlatformProjects
 
 expect sealed class Ops()

compiler/testData/ir/irText/errors/unresolvedReference.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !IGNORE_ERRORS
 
 val test1 = unresolved

compiler/testData/ir/irText/expressions/badBreakContinue.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !IGNORE_ERRORS
 
 fun test1() {

compiler/testData/ir/irText/expressions/badInlinedBreakContinue.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +BreakContinueInInlineLambdas
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !IGNORE_ERRORS
 // WITH_STDLIB
 

compiler/testData/ir/irText/expressions/kt24804.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 inline fun foo() = false
 
 fun run(x: Boolean, y: Boolean): String {

compiler/testData/ir/irText/expressions/kt42321.kt

@@ -1,5 +1,5 @@
 // !LANGUAGE: -ApproximateIntegerLiteralTypesInReceiverPosition
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // SKIP_KT_DUMP
 // This test exists only to check that we don't accidentally break the buggy behavior of the old JVM backend in JVM IR (KT-42321).
 // Feel free to remove it as soon as there's no language version where such code is allowed (KT-38895).

compiler/testData/ir/irText/expressions/primitivesImplicitConversions.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: -ApproximateIntegerLiteralTypesInReceiverPosition
-// IGNORE_BACKEND_FIR: ANY
+// IGNORE_BACKEND_K2: ANY
 // For reasons this test is ignored, go to KT-46419
 
 val test1: Long = 42

compiler/testData/ir/irText/expressions/sam/arrayAsVarargAfterSamArgument.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // TARGET_BACKEND: JVM
 // !LANGUAGE: -ProhibitVarargAsArrayAfterSamArgument
 // WITH_JDK

compiler/testData/ir/irText/expressions/signedToUnsignedConversions.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // WITH_STDLIB
 
 // FILE: signedToUnsignedConversions_annotation.kt

compiler/testData/ir/irText/expressions/whenWithSubjectVariable.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND_FIR: JVM_IR
+// IGNORE_BACKEND_K2: JVM_IR
 // !LANGUAGE: +VariableDeclarationInWhenSubject
 
 fun foo(): Any = 1