[Perl/perl5] 734e45: perlapi: Consolidate SvPVX-ish entries

[Karl Williamson via perl5-changes]

  Branch: refs/heads/smoke-me/khw-docs_pr
  Home:   https://github.com/Perl/perl5
  Commit: 734e45625fe21ef23cb34d56fce27ddbec35807d
      
https://github.com/Perl/perl5/commit/734e45625fe21ef23cb34d56fce27ddbec35807d
  Author: Karl Williamson <k...@cpan.org>
  Date:   2020-11-22 (Sun, 22 Nov 2020)

  Changed paths:
    M sv.h

  Log Message:
  -----------
  perlapi: Consolidate SvPVX-ish entries