bug#74245: 30.0.92; CPerl subroutine signatures are left open when last param is $

[Peter Oliver]

Perl subroutine signatures can include a variable with no name, just a bare $, 
to indicate that a parameter should be ignored.  If this happens in the last 
place, CPerl mode in Emacs 30.0.92 mishandles it, and is unable to see the 
closing ).  Consequently, it matches parentheses incorrectly, and misindents 
subsequent blocks.

I have a test that I will send in as a patch, once I have a bug number.

This issue is not present in Emacs 29.4.

--
Peter Oliver