Fix compilation

Author: MBkkt

libcxx/include/string

@@ -3244,7 +3244,7 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::re
   if (__requested_capacity <= capacity())
     return;
 
-  __target_capacity = __recommend(__target_capacity);
+  size_type __target_capacity = __recommend(__target_capacity);
   if (__target_capacity == capacity())
     return;