[Perl/perl5] 83af6b: perlfunc - mention that rename sets $! on failure

[Dan Book via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 83af6b626c6925bf6b3b47699049003954c1aa56
      
https://github.com/Perl/perl5/commit/83af6b626c6925bf6b3b47699049003954c1aa56
  Author: Dan Book <gri...@grinnz.com>
  Date:   2021-02-17 (Wed, 17 Feb 2021)

  Changed paths:
    M pod/perlfunc.pod

  Log Message:
  -----------
  perlfunc - mention that rename sets $! on failure