[Bug c++/77299] New: No warning for unused "INT64_MAX" and similar constants

[wipedout at yandex dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77299

            Bug ID: 77299
           Summary: No warning for unused "INT64_MAX" and similar
                    constants
           Product: gcc
           Version: 6.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: wipedout at yandex dot ru
  Target Milestone: ---

On http://gcc.godbolt.org/ I select gcc 6.1 and specify -O3 -Wall

The code is:

#include <stdint.h>

int main()
{
  INT64_MIN; // no warning
  INT64_MIN; // no warning
  INT64_MAX; // -Wunused-value
  INT64_MAX; // -Wunused-value
  1; // -Wunused-value
  0; // -Wunused-value
  INT64_MIN + 0; // -Wunused-value
}

For some reason there's no warning where unused INT64_MIN occurs.