* Enable jitdump profiling support by default
This the result of some of the investigation I was doing for #1017. I've
done a number of refactorings here which culminated in a number of
changes that all amount to what I think should result in jitdump support being
enabled by default:
* Pass in a list of finished functions instead of just a range to
ensure that we're emitting jit dump data for a specific module rather
than a whole `CodeMemory` which may have other modules.
* Define `ProfilingStrategy` in the `wasmtime` crate to have everything
locally-defined
* Add support to the C API to enable profiling
* Documentation added for profiling with jitdump to the book
* Split out supported/unsupported files in `jitdump.rs` to avoid having
lots of `#[cfg]`.
* Make dependencies optional that are only used for `jitdump`.
* Move initialization up-front to `JitDumpAgent::new()` instead of
deferring it to the first module.
* Pass around `Arc<dyn ProfilingAgent>` instead of
`Option<Arc<Mutex<Box<dyn ProfilingAgent>>>>`
The `jitdump` Cargo feature is now enabled by default which means that
our published binaries, C API artifacts, and crates will support
profiling at runtime by default. The support I don't think is fully
fleshed out and working but I think it's probably in a good enough spot
we can get users playing around with it!
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!
Alex Crichton
3b7cb6ee64