Accidentally left removed #434 when I meant to add it back in! Updates the `wast` crate dependency and adds support for translating `v128.const` instructions to a `RuntimeValue` Closes #441
This is the wasmtime-wast crate, which contains an implementation of WebAssembly's
"wast" test scripting language, which is used in the
WebAssembly spec testsuite, using wasmtime for execution.