taint REGEX SVs as well as refs to them

Now that REGEX is actually a first-class SV type, we can taint
the regex SV directly, as well as the RV pointing to it.

This means that this now taints:

    $rr = qr/$tainted/;
    $r = $$r;
    /$r/;

1 files changed, 3 insertions, 1 deletions

diff --git a/pp_hot.c b/pp_hot.c
index 4fb5f01aab..e452f07b54 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1235,8 +1235,10 @@ PP(pp_qr)
 	(void)sv_bless(rv, stash);
     }
 
-    if (RX_EXTFLAGS(rx) & RXf_TAINTED)
+    if (RX_EXTFLAGS(rx) & RXf_TAINTED) {
         SvTAINTED_on(rv);
+        SvTAINTED_on(SvRV(rv));
+    }
     XPUSHs(rv);
     RETURN;
 }