[MERGE #4048 @sigatrev] ARM64: GenerateFastNeg
[MERGE #4048 @sigatrev] ARM64: GenerateFastNeg

Merge pull request #4048 from sigatrev:generateFastNeg

update for 64bit tagging, reflecting the amd64 version

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