Add _LIBCPP_ASSERT_INTERNAL

Author: winner245

libcxx/include/bitset

@@ -464,9 +464,11 @@ protected:
     return __const_reference(&__first_, __storage_type(1) << __pos);
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t __pos) _NOEXCEPT {
+    _LIBCPP_ASSERT_INTERNAL(__pos < __bits_per_word, "Out of bounds access in the single word bitset implementation.");
     return __iterator(&__first_, __pos);
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
+    _LIBCPP_ASSERT_INTERNAL(__pos < __bits_per_word, "Out of bounds access in the single word bitset implementation.");
     return __const_iterator(&__first_, __pos);
   }