Enforce disabled features in WastParser for extended-const and memory64?

[keithw]

In some cases, WastParser rejects constructs that use disabled features (e.g. multi-memory, exceptions) and in some cases it appears to allow them (e.g. extended-const, memory64) even if disabled. (As seen in https://github.com/WebAssembly/wabt/pull/2234 where the lack of --enable-extended-const didn't affect wast2json.)

Do we think it's important for wat2wasm to reject these constructs if disabled (and if so, should the spec testsuite or our regression tests include these kinds of negative examples)?

Related to https://github.com/WebAssembly/wabt/issues/1837

[sbc100]

I would say its more correct to reject those features.. but I don't think we should prioritize that work. Its seems fairly minor.