updated for version 7.3.1149

Problem:    New regexp engine: Matching plain text could be faster.
Solution:   Detect a plain text match and handle it specifically.  Add
            vim_regfree().

src/ex_eval.c

@@ -1576,7 +1576,7 @@ ex_catch(eap)
 		    caught = vim_regexec_nl(&regmatch, current_exception->value,
 			    (colnr_T)0);
 		    got_int |= prev_got_int;
-		    vim_free(regmatch.regprog);
+		    vim_regfree(regmatch.regprog);
 		}
 	    }
 	}