JavaScript integration

[bakkot]

I didn't see anything about integration with the JS interface, apologies if I've missed this.

Specifically, the WebAssembly.Memory constructor takes a number of pages and does not (currently) have anything which specifies page size. Probably it should just take an additional option in the options bag to specify the page size? Also it might be good to expose the page size on the Memory objects as well, since .grow also works in units of page size and you really want to know if you're growing by N bytes or N*64k bytes.

[fitzgen]

Agreed that exposing page size in the JS API is a good idea. I don't have strong opinions on the exact APIs.

I'd be interested in the opinions of Web engine representatives here. cc @eqrion @jakobkummerow

[jakobkummerow]

No opinion. I don't expect Web deployments to use custom page sizes anyway.