[Perl/perl5] c50e79: gh17746: add missing check on hardcount

[Hugo van der Sanden via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: c50e79de5d7380bf4269155ab659ec3f66d5aa35
      
https://github.com/Perl/perl5/commit/c50e79de5d7380bf4269155ab659ec3f66d5aa35
  Author: Hugo van der Sanden <h...@crypt.org>
  Date:   2022-03-21 (Mon, 21 Mar 2022)

  Changed paths:
    M regexec.c
    M t/re/re_tests

  Log Message:
  -----------
  gh17746: add missing check on hardcount

Failing to check for max iterations caused an assertion failure.