[Perl/perl5] fb5c7c: readline ARGV: don't try to open '|-' or '-|' and ...

[Tony Cook via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: fb5c7cea820da4e5609bea7c575bcf6dc988b2ea
      
https://github.com/Perl/perl5/commit/fb5c7cea820da4e5609bea7c575bcf6dc988b2ea
  Author: Tony Cook <t...@develop-help.com>
  Date:   2023-08-01 (Tue, 01 Aug 2023)

  Changed paths:
    M doio.c
    M embed.fnc
    M embed.h
    M pod/perldiag.pod
    M proto.h
    M t/io/argv.t

  Log Message:
  -----------
  readline ARGV: don't try to open '|-' or '-|' and warn

This has no effect on in-place editing nor on the <<>> operator.

Later modified to ignore leading/internal/trailing space when
checking the name.

Fixes #21176