* Tweak the API of the `Val` type A few updates to the API of the `Val` type: * Added a payload for `V128`. * Replace existing accessor methods with `Option`-returning versions. * Add `unwrap_xxx` family of methods to extract a value and panic. * Remove `Into` conversions which panic, since panicking in `From` or `Into` isn't idiomatic in Rust * Add documentation to all methods/values/enums/etc. * Rename `Val::default` to `Val::null` * Run rustfmt * Review comments
This crate implements a prototype of the wasm interface types proposal for Wasmtime.