[MERGE #2595 @kfarnung] Adding missed PR feedback for JsCreatePromise
[MERGE #2595 @kfarnung] Adding missed PR feedback for JsCreatePromise

Merge pull request #2595 from kfarnung:jsrtpromise

mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore