[IR] Don't print multifile/synthetic facade class names in irText tests

This only applies to JVM and fq-names in declaration references
in IR dumps.

This enables us to run more irText tests on platforms other than JVM
(see KT-58605).

compiler/testData/ir/irText/declarations/contextReceivers/arrayAccessOperators.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +ContextReceivers
-// IGNORE_BACKEND: JS_IR
 
 data class MyContainer(var s: String)