stop callers of rex engine using RX_MATCH_UTF8_set

The way that the regex engine knows that the match string is utf8 is
currently a complete mess. It's partially signalled by the utf8 flag of
the passed SV, but also by the RXf_MATCH_UTF8 flag in the regex itself,
and the value of PL_reg_match_utf8.

Currently all the callers of the engine (such as pp_match, pp_split etc)
initially use RX_MATCH_UTF8_set() before calling the engine. This sets both
the RXf_MATCH_UTF8 flag on the regex, and PL_reg_match_utf8.

Then the two entry points to the engine (regexec_flags() and
re_intuit_start()) initially repeat the RX_MATCH_UTF8_set()
themselves.

Remove the usage of RX_MATCH_UTF8_set() by the callers of the engine,
and instead just rely on the engine to do it.

Also, remove the "secret" setting of PL_reg_match_utf8 by
RX_MATCH_UTF8_set(), and do it explicitly.

This is a prelude to eliminating PL_reg_match_utf8.

1 files changed, 0 insertions, 1 deletions

diff --git a/pp_ctl.c b/pp_ctl.c
index b0bc528bae..6f2ab5a850 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -214,7 +214,6 @@ PP(pp_substcont)
     }
 
     rxres_restore(&cx->sb_rxres, rx);
-    RX_MATCH_UTF8_set(rx, DO_UTF8(cx->sb_targ));
 
     if (cx->sb_iters++) {
 	const I32 saviters = cx->sb_iters;