Test infra: refactor IGNORE_BACKEND directive

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

compiler/testData/codegen/boxInline/smap/anonymous/objectOnInlineCallSite.smap

@@ -11,20 +11,20 @@ _2Kt
 + 2 1.kt
 builders/_1Kt
 *L
-1#1,35:1
-18#1,3:37
-21#1,8:41
-9#2:36
-9#2:40
+1#1,34:1
+17#1,3:36
+20#1,8:40
+8#2:35
+8#2:39
 *S KotlinDebug
 *F
 + 1 2.kt
 _2Kt
 *L
-33#1:37,3
-33#1:41,8
-20#1:36
-33#1:40
+32#1:36,3
+32#1:40,8
+19#1:35
+32#1:39
 *E
 
 SMAP
@@ -35,7 +35,7 @@ Kotlin
 + 1 2.kt
 _2Kt$test$1$1
 *L
-1#1,35:1
+1#1,34:1
 *E
 
 SMAP
@@ -46,6 +46,6 @@ Kotlin
 + 1 2.kt
 _2Kt$test$1$1
 *L
-1#1,35:1
+1#1,34:1
 *E