regcomp.c: Silence compiler warning about longjump

I believe that there isn't a code path that can screw this up, but one
compiler at least believes otherwise.  Declaring it volatile should fix
that.

1 files changed, 1 insertions, 1 deletions

diff --git a/regcomp.c b/regcomp.c
index d7cb993649..595fc6f8e6 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -4523,7 +4523,7 @@ Perl_re_compile(pTHX_ SV * const pattern, U32 orig_pm_flags)
     struct regexp *r;
     register regexp_internal *ri;
     STRLEN plen;
-    char  *exp;
+    VOL char  *exp;
     char* xend;
     regnode *scan;
     I32 flags;