Add WebAssembly exception handling spec?

[Elchi3]

https://webassembly.github.io/exception-handling/js-api/index.html is a spec that describes new JavaScript built-ins Exception and Tag. They are shipping in Safari 15.2.

BCD PR: mdn/browser-compat-data#14910

Add this spec to browser-specs?

[dontcallmedom]

Hmm... The situation is a bit confusing: https://webassembly.github.io/exception-handling/js-api/index.html seems to be a superset of https://webassembly.github.io/spec/js-api/, but uses the same "this version" and "TR latest" URIs. I'm not quite sure why it exists separately from the main spec in the first place.

@Ms2ger can you help us figure out how we should handle these two documents?

[Ms2ger]

This is how the wasm cg works, for better or worse: every proposal has its own fork of the full spec repo, so at any point, there's a number of different (and hopefully compatible) supersets of the main spec floating around. I tried to fix the urls here: WebAssembly/exception-handling#199.

[dontcallmedom]

Thanks for the explanation, which I guess implies we may have to deal with other similar cases.

When does a proposal get merged in the main spec? Is it linked to implementation adoption as for Ecmascript?

[Ms2ger]

At phase 5 as described here: https://github.com/WebAssembly/meetings/blob/main/process/phases.md