This PR updates `wasmtime_wasi` crate by adjusting `poll_oneoff`'s
signature to that introduced in `wasi_common` in
CraneStation/wasi-common#137. This change is required in order to
fix#440.
* Switch lightbeam from `wabt` to `wast`
Switch from a C++-based `*.wat` parser to a Rust-based parser
* Remove unneeded `wabt` dev-dependency from wasmtime-api
* Rewrite `wasmtime-wast` crate with `wast-parser`
This commit moves the `wasmtime-wast` crate off the `wabt` crate on to
the `wast-parser` crate which is a Rust implementation of a `*.wast` and
`*.wat` parser. The intention here is to continue to reduce the amount
of C++ required to build wasmtime!
* Use new `wat` and `wast` crate names
* deps: bump wasmparser to 0.39.2
This has a bug fix for multi-value Wasm validation that is required for getting
the spec tests passing.
https://github.com/yurydelendik/wasmparser.rs/pull/135
* Update cranelift to 0.46.1 to get multi-value Wasm support
The `cranelift_wasm` APIs had to change a little bit to maintain state necessary
when translating multi-value Wasm blocks. The `translate_module` function now
returns a `ModuleTranslationState` that is borrowed during each function's
translation.
* Enable multi-value proposal's spec tests
This enables all the Wasm multi-value proposal's spec tests other than the ones
that rely on functions having more return values than registers available on the
target. That is not supported by cranelift yet.
* wasmtime-interface-types: always use multi-value Wasm
And remove the return pointer hacks that work around the lack of multi-value.
