modernize the documentation about $& and similar variables

[damil]

current documentation about variables $&, etc. still mentions performance penalties ... this is no longer true since Perl 5.20.0

• This set of changes does not require a perldelta entry.

[Grinnz]

perlfaq is maintained on CPAN and so changes to it must be contributed upstream at https://github.com/perl-doc-cats/perlfaq.

[Grinnz]

I'm not certain the $& / /p issue has been completely ameliorated, as has been recently discussed on p5p. Unfortunately the NNTP archives currently seem to be not responding so I cannot link the discussion.

[jkeenan]

I'm not certain the $& / /p issue has been completely ameliorated, as has been recently discussed on p5p. Unfortunately the NNTP archives currently seem to be not responding so I cannot link the discussion.

@Grinnz how do you think we should handle this patch? It changes two files, one of which needs to be sent upstream first, while the other is in P5P jurisdiction? Can one be changed without the other (in either direction)?

[Grinnz]

The changes can be considered separately. The change to the core perldoc should be evaluated on its accuracy by someone with more knowledge of these details than me.

[Grinnz]

Here is the most recent discussion on /p on the list: https://www.nntp.perl.org/group/perl.perl5.porters/2026/02/msg270725.html