[JS TESTS] Disable mangler checker in tests

compiler/testData/codegen/box/enum/enumWithLambdaParameter.kt

@@ -1,4 +1,5 @@
 // KT-4423 Enum with function not compiled
+// SKIP_MANGLE_VERIFICATION
 
 enum class Sign(val str: String, val func: (x: Int, y: Int) -> Int){
     plus("+", { x, y -> x + y }),

compiler/testData/codegen/box/enum/kt20651a.kt

@@ -1,3 +1,4 @@
+// SKIP_MANGLE_VERIFICATION
 enum class Foo(
         val x: String,
         val callback: () -> String

compiler/testData/codegen/box/enum/kt20651b.kt

@@ -1,3 +1,4 @@
+// SKIP_MANGLE_VERIFICATION
 interface Callback {
     fun invoke(): String
 }