[1.8>master] [MERGE #4423 @Cellule] Fix FunctionBody::IsAsmJSModule logic.
[1.8>master] [MERGE #4423 @Cellule] Fix FunctionBody::IsAsmJSModule logic.

Merge pull request #4423 from Cellule:is_asm_module

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