Lots more warnings are showing up on nightly compilers due to a recent change. I've opened rust-lang/rust#66373 on the compiler side for this as well.
This is the wasmtime-runtime crate, which contains wasm runtime library
support, supporting the wasm ABI used by wasmtime-environ,
wasmtime-jit, and wasmtime-obj.
This crate does not make a host vs. target distinction; it is meant to be compiled for the target.