[Perl/perl5] b89c6d: perlapi: Document re_compile

[Karl Williamson via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: b89c6d2bd8814b32e3c062b33b5020046b6cab6d
      
https://github.com/Perl/perl5/commit/b89c6d2bd8814b32e3c062b33b5020046b6cab6d
  Author: Karl Williamson <k...@cpan.org>
  Date:   2022-05-19 (Thu, 19 May 2022)

  Changed paths:
    M embed.fnc
    M regcomp.c

  Log Message:
  -----------
  perlapi: Document re_compile