[Bug gcov-profile/80031] New: gcno files contain BB flags that are not used

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80031

            Bug ID: 80031
           Summary: gcno files contain BB flags that are not used
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

It's probably quite old regression where we unnecessarily emit block flags:

profile.c:

      /* Basic block flags */
      offset = gcov_write_tag (GCOV_TAG_BLOCKS);
      for (i = 0; i != (unsigned) (n_basic_blocks_for_fn (cfun)); i++)
        gcov_write_unsigned (0);
      gcov_write_length (offset);