[MERGE #4126 @aaronsgiles] ARM64: don't set the low bit of return addresses.
[MERGE #4126 @aaronsgiles] ARM64: don't set the low bit of return addresses.

Merge pull request #4126 from aaronsgiles:user/aarongi/work4

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