Revert "fix up async/await"

This reverts commit f18f264a330258da521027cc4edd5852e26f8add.

acorn.js

@@ -2075,7 +2075,7 @@
               retNode = finishNode(retNode, "AssignmentExpression");
             }
             else {
-              unexpected();
+              unexpected
             }
             semicolon();
           }
@@ -2649,8 +2649,6 @@
       }
       if (options.ecmaVersion >= 6) {
         isGenerator = eat(_star);
-        prop.method = false;
-        prop.shorthand = false;
       }
       
       if (tokType === _name || tokType.keyword) {
@@ -2661,9 +2659,18 @@
         if (isAsync && isGenerator) {
           unexpected();
         }
+        if (options.ecmaVersion >= 6) {
+          prop.method = false;
+          prop.shorthand = false;
+        }
         parsePropertyName(prop);
       }
       else if (tokType === _colon) {
+        // key could be "async"
+        if (options.ecmaVersion >= 6) {
+          prop.method = false;
+          prop.shorthand = false;
+        }
         isAsync = false;
       }
       else if (tokType === _bracketL) {

test/tests-harmony.js

@@ -14716,7 +14716,7 @@ test("var async; async = 10;", {
   locations: true
 });
 
-test("var {a, async} = b;", {
+test("var {a, async} = b;" {
   "type": "Program",
   "start": 0,
   "end": 19,