* Move `Func` to its own file * Support `Func` imports with zero shims This commit extends the `Func` type in the `wasmtime` crate with static `wrap*` constructors. The goal of these constructors is to create a `Func` type which has zero shims associated with it, creating as small of a layer as possible between wasm code and calling imported Rust code. This is achieved by creating an `extern "C"` shim function which matches the ABI of what Cranelift will generate, and then the host function is passed directly into an `InstanceHandle` to get called later. This also enables enough inlining opportunities that LLVM will be able to see all functions and inline everything to the point where your function is called immediately from wasm, no questions asked.
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!