IR text tests: Unmute enum class-related tests

Making enum class-related tests unmuted requires implementing
a special "compatibility" mode for IR tree dumper to filter out
fake override declarations leaking from java.enum.Enum and
kotlin.Enum (JVM-only) classes.

compiler/testData/ir/irText/declarations/annotations/enumsInAnnotationArguments.kt

@@ -1,8 +1,3 @@
-// IGNORE_BACKEND: JS_IR
-
-// KT-61141: absent enum fake_overrides: finalize, getDeclaringClass, clone
-// IGNORE_BACKEND: NATIVE
-
 enum class En { A, B, C, D }
 
 annotation class TestAnn(val x: En)