Previously we initialized trap handling (signals/etc) once-per-instance but that's a bit too granular since we only need to do this as one-time per-program initialization. This moves the initialization to `Store` instead which means that we'll call this at least once per thread, which some platforms may need (none currently do, they all only need per-program initialization, but Fuchsia will need per-thread initialization).
Wasmtime Embedding API
The wasmtime crate is an embedding API of the wasmtime WebAssembly runtime.
This is intended to be used in Rust projects and provides a high-level API of
working with WebAssembly modules.
If you're interested in embedding wasmtime in other languages, you may wish to
take a look a the C embedding API instead!