[Perl/perl5] da37d3: embed.h: Add caution about PERL_NO_SHORT_NAMES

[Karl Williamson via perl5-changes]

  Branch: refs/heads/smoke-me/khw-pr
  Home:   https://github.com/Perl/perl5
  Commit: da37d3190cc92a7e281c96aa5837c04dcc40fae8
      
https://github.com/Perl/perl5/commit/da37d3190cc92a7e281c96aa5837c04dcc40fae8
  Author: Karl Williamson <k...@cpan.org>
  Date:   2020-10-19 (Mon, 19 Oct 2020)

  Changed paths:
    M embed.h
    M regen/embed.pl

  Log Message:
  -----------
  embed.h: Add caution about PERL_NO_SHORT_NAMES