[Bug c++/77999] New: GCC leaks system header diagnostic about reserved names.

[eric at efcs dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77999

            Bug ID: 77999
           Summary: GCC leaks system header diagnostic about reserved
                    names.
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: eric at efcs dot ca
  Target Milestone: ---

Reproducer:
// g++ -std=c++14 -Werror test.cpp
#include <chrono>
using std::chrono::operator ""h; // error emitted on this line.
// {{error: literal operator suffixes not preceded by '_' are reserved for
future standardization}}