Structured cloning of WebAssembly.Memory is not defined

[annevk]

At least Gecko and WebKit support serializing & deserializing WebAssembly.Memory objects. Yet https://webassembly.github.io/spec/web-api/#serialization only covers WebAssembly.Module.

I also couldn't find test coverage for this on WPT.

[eqrion]

Just to clarify, this is only serializing/deserializing shared WebAssembly.Memory right? I don't think Gecko supports doing that for unshared memories. You could make a copy of the underlying ArrayBuffer if you want, but it's not transferable.

Technically the threads proposal hasn't merged yet, and so shared memory isn't defined here yet. I looked upstream though and it is missing a definition for this in the specification there.

[annevk]

I created some tentative tests here to clarify what I mean and what I think the specification needs to require: web-platform-tests/wpt#59748.