[1.8>master] [MERGE #4282 @Cellule] WASM: assert int32 indexes for x64 memory access
[1.8>master] [MERGE #4282 @Cellule] WASM: assert int32 indexes for x64 memory access

Merge pull request #4282 from Cellule:wasm/mem_access_int32_index

OS#14728988
Assert that we can only have int32 indexes for wasm memory operations.
This is to future proof us in case we start accepting int64 and forget to update this code path.

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