[MERGE #3093 @MikeHolman] add jit clamping support in JIT thunk emitter
[MERGE #3093 @MikeHolman] add jit clamping support in JIT thunk emitter

Merge pull request #3093 from MikeHolman:jitclampfix

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