[Perl/perl5] 641b84: keywords.h: Restrict to core

[Karl Williamson via perl5-changes]

  Branch: refs/heads/smoke-me/khw-pr2
  Home:   https://github.com/Perl/perl5
  Commit: 641b847431aa8f19c7835f1c4feb2edcb90691cb
      
https://github.com/Perl/perl5/commit/641b847431aa8f19c7835f1c4feb2edcb90691cb
  Author: Karl Williamson <k...@cpan.org>
  Date:   2020-11-06 (Fri, 06 Nov 2020)

  Changed paths:
    M keywords.c
    M keywords.h
    M regen/keywords.pl

  Log Message:
  -----------
  keywords.h: Restrict to core

These should not be used outside core