Add support for async/streams/futures

This adds support for loading, compiling, linking, and running components which
use the [Async
ABI](https://github.com/WebAssembly/component-model/blob/main/design/mvp/Async.md)
along with the [`stream`, `future`, and
`error-context`](WebAssembly/component-model#405) types.
It also adds support for generating host bindings such that multiple host
functions can be run concurrently with guest tasks -- without monopolizing the
`Store`.

See the [implementation RFC](bytecodealliance/rfcs#38)
for details, as well as [this
repo](https://github.com/dicej/component-async-demo) containing end-to-end smoke
tests.

This is very much a work-in progress, with a number of tasks remaining:

- [ ] Avoid exposing global task IDs to guests and use per-instance IDs instead
- [ ] Track `task.return` type during compilation and assert the actual and expected types match at runtime
- [ ] Ensure all guest pointers are bounds-checked when lifting, lowering, or copying values
- [ ] Reduce code duplication in `wasmtime_cranelift::compiler::component`
- [ ] Reduce code duplication between `StoreContextMut::on_fiber` and `concurrent::on_fiber`
- [ ] Minimize and/or document the use of unsafe code
- [ ] Add support for `(Typed)Func::call_concurrent` per the RFC
- [ ] Add support for multiplexing stream/future reads/writes and concurrent calls to guest exports per the RFC
- [ ] Refactor, clean up, and unify handling of backpressure, yields, and even polling
- [ ] Guard against reentrance where required (e.g. in certain fused adapter calls)
- [ ] Add integration test cases covering new functionality to tests/all/component_model (starting by porting over the tests in https://github.com/dicej/component-async-demo)
- [ ] Add binding generation test cases to crates/component-macro/tests
- [ ] Add WAST tests to tests/misc_testsuite/component-model
- [ ] Add support and test coverage for callback-less async functions (e.g. goroutines)
- [ ] Switch to back to upstream `wasm-tools` once bytecodealliance/wasm-tools#1895 has been merged and released

Signed-off-by: Joel Dice <[email protected]>

Author: dicej

Cargo.lock

@@ -274,15 +274,15 @@ wit-bindgen = { version = "0.34.0", default-features = false }
 wit-bindgen-rust-macro = { version = "0.34.0", default-features = false }
 
 # wasm-tools family:
-wasmparser = { version = "0.219.1", default-features = false }
-wat = "1.219.1"
-wast = "219.0.1"
-wasmprinter = "0.219.1"
-wasm-encoder = "0.219.1"
-wasm-smith = "0.219.1"
-wasm-mutate = "0.219.1"
-wit-parser = "0.219.1"
-wit-component = "0.219.1"
+wasmparser = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wat = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wast = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wasmprinter = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wasm-encoder = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wasm-smith = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wasm-mutate = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wit-parser = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
+wit-component = { git = "https://github.com/dicej/wasm-tools", branch = "async" }
 
 # Non-Bytecode Alliance maintained dependencies:
 # --------------------------