[Perl/perl5] 0d564a: av.h - document new newAV_mortal macro

[Richard Leach via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 0d564a3d013287cf0880fdc3264f30c20fe6188d
      
https://github.com/Perl/perl5/commit/0d564a3d013287cf0880fdc3264f30c20fe6188d
  Author: Richard Leach <richardle...@users.noreply.github.com>
  Date:   2024-02-05 (Mon, 05 Feb 2024)

  Changed paths:
    M av.h

  Log Message:
  -----------
  av.h - document new newAV_mortal macro