Fix xref-find-references on MS-Windows

* lisp/cedet/semantic/symref/grep.el
(semantic-symref-derive-find-filepatterns): Use
'shell-quote-argument' instead of manually quoting in a way that
only works with Posix shells.  (Bug#22289)

lisp/cedet/semantic/symref/grep.el

@@ -75,14 +75,14 @@ Optional argument MODE specifies the `major-mode' to test."
 	  )))
     ;; Convert the list into some find-flags.
     (cond ((= (length pat) 1)
-	   (concat "-name \"" (car pat) "\""))
+	   (concat "-name " (shell-quote-argument (car pat))))
 	  ((consp pat)
-	   (concat "\\( "
+	   (concat (shell-quote-argument "(") " "
 		   (mapconcat (lambda (s)
-				(concat "-name \"" s "\""))
+				(concat "-name " (shell-quote-argument s)))
 			      pat
 			      " -o ")
-		   " \\)"))
+		   " " (shell-quote-argument ")")))
 	  (t
 	   (error "Customize `semantic-symref-filepattern-alist' for %s" major-mode))
 	  )))