Use zend_string for subpat_names table

When used with preg_match_all or preg_replace_callback(_array),
subpattern names can be used in the matches array many times.
Switch the subpat_names table to use zend_string, so we don't have
to allocate a new string every time. Also don't bother creating the
table if no $matches were passed.

This might be a regression for the case where preg_match() is used
with many trailing named subpatterns that are skipped in the result
array, but that seems rather contrived.

0 files changed, 0 insertions, 0 deletions