[MERGE #5555 @MikeHolman] fix bug where we weren't setting bytecode offset for a backend instr
[MERGE #5555 @MikeHolman] fix bug where we weren't setting bytecode offset for a backend instr

Merge pull request #5555 from MikeHolman:missingoffset

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