Fix for TeX-local-master-p

[Ikumi Keita]

Hi all,

I noticed that `TeX-local-master-p' doesn't work in Texinfo mode because
it hard-codes comment prefix as "%". Due to this inconsistency, in
texinfo document buffer, the menu item Texinfo->Multifile/Parsing->Set
master file (C-c _) isn't grayed out even when it has valid
"TeX-master:" entry in Local Variables section.

Now that all emacsens supported by AUCTeX have
`file-local-variables-alist', how about the attached patch? It fixes
bug#33227[1] also.
[1] https://debbugs.gnu.org/cgi/bugreport.cgi?bug=33227

Best,
Ikumi Keita

diff
Description: fix for TeX-local-master-p