Added SpreadElement support.

testFail message fixes for object methods.

acorn.js

@@ -1734,6 +1734,9 @@
     case _new:
       return parseNew();
 
+    case _ellipsis:
+      return parseSpread();
+
     default:
       unexpected();
     }
@@ -1752,6 +1755,15 @@
     return finishNode(node, "NewExpression");
   }
 
+  // Parse spread element '...expr'
+
+  function parseSpread() {
+    var node = startNode();
+    next();
+    node.argument = parseExpression(true);
+    return finishNode(node, "SpreadElement");
+  }
+
   // Parse an object literal.
 
   function parseObj() {

test/tests-harmony.js

@@ -15773,9 +15773,9 @@ testFail("x \n isnt y", "Unexpected token (2:7)", {ecmaVersion: 6});
 
 testFail("function default() {}", "Unexpected token (1:9)", {ecmaVersion: 6});
 
-testFail("function hello() {'use strict'; ({ i: 10, s(eval) { } }); }", "Unexpected token (1:45)", {ecmaVersion: 6});
+testFail("function hello() {'use strict'; ({ i: 10, s(eval) { } }); }", "Defining 'eval' in strict mode (1:44)", {ecmaVersion: 6});
 
-testFail("function a() { \"use strict\"; ({ b(t, t) { } }); }", "Unexpected token (1:38)", {ecmaVersion: 6});
+testFail("function a() { \"use strict\"; ({ b(t, t) { } }); }", "Argument name clash in strict mode (1:37)", {ecmaVersion: 6});
 
 testFail("var super", "Unexpected token (1:5)", {ecmaVersion: 6});