[1.8>master] [MERGE #4523 @Cellule] WASM: Bytecode reset assert
[1.8>master] [MERGE #4523 @Cellule] WASM: Bytecode reset assert

Merge pull request #4523 from Cellule:wasm/bytecode_reset_assert

Add asserts to catch cases where we would reset the bytecode block to nullptr.

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