For 19.33-19.34 only (bumps CPerl-related functionality to the level of 20.3):

patch_emacs_1933_syntax_assist.gz
Makes Emacs recognize `syntax-table' text property => 99.99%-valid
Perl parsing. (rms-emacs-20.2-patch-inf-loop is included, but not
the other bug fixes available for 20.2)

diff_emacs1933_repeated_parse
Makes Emacs return correct enclosing-block data from `parse-partial-sexp'
even if parsing is split into several steps => orders-of-magnitude
quickier indentation.

For 20.1-20.2 only (bumps CPerl-related functionality to the level of 20.3)

diff_emacs20_2_94_repeated_parse
See `diff_emacs1933_repeated_parse'.

rms-emacs-20.2-experimental-patch-narrow+dirfiles+skipcomment+skipsyntax-better
A must for 20.2 for some usages (Arg out of range and similar
error messages with GNUS, narrow-buffer and others).

rms-emacs-20.2-patch-inf-loop
A must for 20.2 if Emacs "hangs" in CPerl-mode (you need C-g to unhang)