Merge branch 'master' into harmony

lib/parse.js

@@ -480,7 +480,11 @@ function tokenizer($TEXT, filename, html5_comments) {
             regexp += ch;
         }
         var mods = read_name();
-        return token("regexp", new RegExp(regexp, mods));
+        try {
+          return token("regexp", new RegExp(regexp, mods));
+        } catch(e) {
+          parse_error(e.message);
+        }
     });
 
     function read_operator(prefix) {