[Perl/perl5] ff7e37: locale.c: Add warning if function return ignored

[Karl Williamson via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: ff7e37d5ca2e55a1e53e5b375e3cc9aedc9ce4ec
      
https://github.com/Perl/perl5/commit/ff7e37d5ca2e55a1e53e5b375e3cc9aedc9ce4ec
  Author: Karl Williamson <k...@cpan.org>
  Date:   2023-07-12 (Wed, 12 Jul 2023)

  Changed paths:
    M embed.fnc
    M proto.h

  Log Message:
  -----------
  locale.c: Add warning if function return ignored