[MERGE #751] Add a cast when using scoped enum as an array size.
[MERGE #751] Add a cast when using scoped enum as an array size.

Merge pull request #751 from Rastaban:master
This is not allowed in standard C++, and will be enforced in future relases of MSVC.

There is already casts when the array is indexed, so no additional changes
are needed at this time.

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