Adopt @philnik777's review comments

Author: frederick-vs-ja

libcxx/include/__algorithm/sort.h

@@ -861,8 +861,7 @@ template <class _AlgPolicy, class _RandomAccessIterator, class _Comp>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
 __sort_dispatch(_RandomAccessIterator __first, _RandomAccessIterator __last, _Comp& __comp) {
   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-  difference_type __depth_limit = static_cast<difference_type>(
-      2 * std::__bit_log2(static_cast<__make_unsigned_t<difference_type> >(__last - __first)));
+  difference_type __depth_limit = 2 * std::__bit_log2(std::__to_unsigned_like(__last - __first));
 
   // Only use bitset partitioning for arithmetic types.  We should also check
   // that the default comparator is in use so that we are sure that there are no