Update string

Author: MBkkt

libcxx/include/string

@@ -2279,6 +2279,7 @@ private:
   }
   enum { __alignment = 8 };
   static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __recommend(size_type __s) _NOEXCEPT {
+    _LIBCPP_ASSERT_INTERNAL(__s >= __min_cap, "recommend is called for small string capacity");
     const size_type __boundary = sizeof(value_type) < __alignment ? __alignment / sizeof(value_type) : __endian_factor;
     size_type __guess          = __align_it<__boundary>(__s + 1) - 1;
     _LIBCPP_ASSERT_INTERNAL(__guess >= __s, "recommendation is below the requested size");