ES6: Add support for method shorthand in object literals

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index 00d8a88d7342222a04357665c0b4ae9f11c0501b..b75d760499466566647cc9407b347e99940185c5 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -1767,7 +1767,10 @@ function FunctionSourceString(func) {
   var name = %FunctionNameShouldPrintAsAnonymous(func)
       ? 'anonymous'
       : %FunctionGetName(func);
-  var head = %FunctionIsGenerator(func) ? 'function* ' : 'function ';
+
+  var head = %FunctionIsConciseMethod(func)
+      ? ''
+      : %FunctionIsGenerator(func) ? 'function* ' : 'function ';
   return head + name + source;
 }