[MERGE #4135 @sigatrev] ARM64: shift branch
[MERGE #4135 @sigatrev] ARM64: shift branch

Merge pull request #4135 from sigatrev:shiftbranch

There are no arm64 shift opcodes that set flags, so use a test branch instead.

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