AK: Add ptr_hash to use int_hash or u64_hash depending on pointer size

Author: https://github.com/jcs
Commit: 7e6ac544f7
Pull-request: https://github.com/SerenityOS/serenity/pull/1233
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/bugaevc

AK/OwnPtr.h

@@ -204,7 +204,7 @@ inline void swap(OwnPtr<T>& a, OwnPtr<U>& b)
 template<typename T>
 struct Traits<OwnPtr<T>> : public GenericTraits<OwnPtr<T>> {
     using PeekType = const T*;
-    static unsigned hash(const OwnPtr<T>& p) { return int_hash((u32)p.ptr()); }
+    static unsigned hash(const OwnPtr<T>& p) { return ptr_hash(p.ptr()); }
     static bool equals(const OwnPtr<T>& a, const OwnPtr<T>& b) { return a.ptr() == b.ptr(); }
 };