Suppress UNCHECKED_CAST instead of CAST_NEVER_SUCCEEDS in several places

This is related to KT-6611 being fixed recently. Note that not all cases of
incorrect "cast never succeeds" were fixed

core/builtins/src/kotlin/ArrayIntrinsics.kt

@@ -22,5 +22,5 @@ import kotlin.internal.PureReifiable
  * Returns an empty array of the specified type [T].
  */
 public inline fun <reified @PureReifiable T> emptyArray(): Array<T> =
-        @Suppress("CAST_NEVER_SUCCEEDS")
-        arrayOfNulls<T>(0) as Array<T>
+        @Suppress("UNCHECKED_CAST")
+        (arrayOfNulls<T>(0) as Array<T>)