accept IdentifierName in property-name context

lib/jsparse.js

@@ -927,6 +927,18 @@ Narcissus.parser = (function() {
         return new Node(t, { type: IDENTIFIER });
     }
 
+    /*
+     * IdentifierName :: (tokenizer) -> IDENTIFIER node
+     */
+    function IdentifierName(t) {
+        if (t.match(IDENTIFIER))
+            return new Node(t, { type: IDENTIFIER });
+        t.get();
+        if (t.token.value in definitions.keywords)
+            return new Node(t, { type: IDENTIFIER });
+        throw t.newSyntaxError("missing IdentifierName");
+    }
+
     /*
      * QualifiedPath :: (tokenizer, compiler context) -> (IDENTIFIER | DOT) node
      */
@@ -1597,8 +1609,7 @@ Narcissus.parser = (function() {
               case DOT:
                 n2 = new Node(t);
                 n2.push(n);
-                t.mustMatch(IDENTIFIER);
-                n2.push(new Node(t));
+                n2.push(IdentifierName(t));
                 break;
 
               case LEFT_BRACKET: