[es6] re-implement rest parameters via desugaring

src/runtime.js

Index: src/runtime.js
diff --git a/src/runtime.js b/src/runtime.js
index e5ac2210528c7ef46d58f05de1cb0b41468498c2..79c317108ac40f9c21591b3afa59e4bfb26ee795 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -63,6 +63,8 @@ var TO_NUMBER;
 var TO_STRING;
 var TO_NAME;
 
+var $createEmptyArray;
+var $createStrongEmptyArray;
 var $defaultNumber;
 var $defaultString;
 var $NaN;
@@ -966,6 +968,15 @@ function ToPositiveInteger(x, rangeErrorIndex) {
   return i;
 }
 
+function CreateEmptyArray() {
+  return [];
+}
+
+function CreateStrongEmptyArray() {
+  "use strong";
+  return [];
+}
+
 //----------------------------------------------------------------------------
 
 // NOTE: Setting the prototype for Array must take place as early as
@@ -996,5 +1007,7 @@ $toPositiveInteger = ToPositiveInteger;
 $toPrimitive = ToPrimitive;
 $toString = ToString;
 $toUint32 = ToUint32;
+$createEmptyArray = CreateEmptyArray
+$createStrongEmptyArray = CreateStrongEmptyArray;
 
 })