Support structured cloning of ES'15 Map and Set

LayoutTests/fast/storage/resources/serialized-script-value.js

-var kSerializedScriptValueVersion = 8;
+var kSerializedScriptValueVersion = 9;
 
 function forVersion(version, values) {
     var versionTag = 0xff;
     var versionPrefix = [ (version << 8) | versionTag ];
 
     return versionPrefix.concat(values)
 }
 
 function expectBufferValue(bytesPerElement, expectedValues, buffer) {
     expectedBufferValues = expectedValues;
@@ skipping 191 matching lines @@
 }
 
 function testFileSerialization() {
     window.jsTestIsAsync = true;
     testConstructedFileSerialization(function () {
         testUserSelectedFileSerialization(function () {
           finishJSTest();
         });
     });
 }