Fix compiler warning of extraneous parentheses

[trixirt]

Summary

Building with clang 5 produces this warning

...lib/Support/regengine.inc:706:13: warning: equality comparison with extraneous parentheses [-Wparentheses-equality]

if (((st) == (fresh)))

Inspection of the EQ macro shows that the ()'s in the if-check are not needed.

[xbolva00]

Please upload patch with full context

[trixirt]

More content.

[dblaikie]

This doesn't have a huge scope to worry about so maybe thinking about it this hard is unnecessary: but I'm sort of undecided what the "right thing" to do here is, seems like maybe clang shouldn't warn on a construct like this? but that's a lot to do for a tiny case like this that hasn't come up elsewhere...

[trixirt]

This change fixes one of the few build warnings.
The extra parenthesis warning is noisy.
I agree there isn't an obvious best path.
I commented the code for this reason.

lib/Support/regengine.inc

fast(struct match *m, const char *start, const char *stop, sopno startst,
   st = step(m->g, startst, stopst, st, NOTHING, st);
   ASSIGN(fresh, st);
   SP("start", st, *p);
   coldp = NULL;
   for (;;) {
     /* next character */
     lastc = c;
     c = (p == m->endp) ? OUT : *p;
-    if (EQ(st, fresh))
+    /* EQ has ()'s, so another set for 'if' is not necessary */
+    if EQ(st, fresh)
       coldp = p;
 
     /* is there an EOL and/or BOL between lastc and c? */
     flagch = '\0';
     i = 0;
     if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
         (lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
       flagch = BOL;