[K2/N] KT-55828: Enable fixed tests

Merge-request: KT-MR-9246
Merged-by: Vladimir Sukharev <Vladimir.Sukharev@jetbrains.com>

compiler/testData/codegen/box/casts/mutableCollections/asWithMutable.kt

@@ -1,7 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
-
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()
 class MItr : MutableIterator<String> by ArrayList<String>().iterator()

compiler/testData/codegen/box/casts/mutableCollections/isWithMutable.kt

@@ -1,6 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()
 class MItr : MutableIterator<String> by ArrayList<String>().iterator()

compiler/testData/codegen/box/casts/mutableCollections/reifiedAsWithMutable.kt

@@ -1,7 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
-
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()
 class MItr : MutableIterator<String> by ArrayList<String>().iterator()

compiler/testData/codegen/box/casts/mutableCollections/reifiedIsWithMutable.kt

@@ -1,6 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()
 class MItr : MutableIterator<String> by ArrayList<String>().iterator()

compiler/testData/codegen/box/casts/mutableCollections/reifiedSafeAsWithMutable.kt

@@ -1,6 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
 
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()

compiler/testData/codegen/box/casts/mutableCollections/safeAsWithMutable.kt

@@ -1,7 +1,4 @@
 // WITH_STDLIB
-// KT-55828
-// IGNORE_BACKEND_K2: NATIVE
-
 
 class Itr : Iterator<String> by ArrayList<String>().iterator()
 class MItr : MutableIterator<String> by ArrayList<String>().iterator()