[JS IR BE] Update test data

compiler/testData/codegen/box/functions/coerceVoidToArray.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 fun a(): IntArray? = null
 
 fun b(): Nothing = throw Exception()

compiler/testData/codegen/box/functions/coerceVoidToObject.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 fun a(): String? = null
 
 fun b(): Nothing = throw Exception()

compiler/testData/codegen/box/functions/invoke/kt3297.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 //KT-3297 Calling the wrong function inside an extension method to the Function0 class
 
 infix fun <R> Function0<R>.or(alt: () -> R): R {