LibJS: Make array_merge_sort() public

Userland/Libraries/LibJS/Runtime/ArrayPrototype.cpp

@@ -867,7 +867,7 @@ JS_DEFINE_NATIVE_FUNCTION(ArrayPrototype::reverse)
     return this_object;
 }
 
-static ThrowCompletionOr<void> array_merge_sort(VM& vm, GlobalObject& global_object, FunctionObject* compare_func, MarkedVector<Value>& arr_to_sort)
+ThrowCompletionOr<void> array_merge_sort(VM& vm, GlobalObject& global_object, FunctionObject* compare_func, MarkedVector<Value>& arr_to_sort)
 {
     // FIXME: it would probably be better to switch to insertion sort for small arrays for
     // better performance

Userland/Libraries/LibJS/Runtime/ArrayPrototype.h

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2020-2022, Linus Groh <linusg@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -58,4 +58,6 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(group_to_map);
 };
 
+ThrowCompletionOr<void> array_merge_sort(VM&, GlobalObject&, FunctionObject* compare_func, MarkedVector<Value>& arr_to_sort);
+
 }