* Migrate from `winapi` to `windows-sys`
I believe that Microsoft itself is supporting the development of
`windows-sys` and it's also used by `cap-std` now so this switches
Wasmtime's dependencies on Windows APIs from the `winapi` crate to the
`windows-sys` crate. We still have `winapi` in our dependency graph but
that may get phased out over time.
* Make windows-sys a target-specific dependency
* Upgrade all crates to the Rust 2021 edition
I've personally started using the new format strings for things like
`panic!("some message {foo}")` or similar and have been upgrading crates
on a case-by-case basis, but I think it probably makes more sense to go
ahead and blanket upgrade everything so 2021 features are always
available.
* Fix compile of the C API
* Fix a warning
* Fix another warning
This pulls in a fix for Android, where Android's seccomp policy on older
versions is to make `openat2` irrecoverably crash the process, so we have
to do a version check up front rather than relying on `ENOSYS` to
determine if `openat2` is supported.
And it pulls in the fix for the link errors when multiple versions of
rsix/rustix are linked in.
And it has updates for two crate renamings: rsix has been renamed to
rustix, and unsafe-io has been renamed to io-extras.
* Use rsix to make system calls in Wasmtime.
`rsix` is a system call wrapper crate that we use in `wasi-common`,
which can provide the following advantages in the rest of Wasmtime:
- It eliminates some `unsafe` blocks in Wasmtime's code. There's
still an `unsafe` block in the library, but this way, the `unsafe`
is factored out and clearly scoped.
- And, it makes error handling more consistent, factoring out code for
checking return values and `io::Error::last_os_error()`, and code that
does `errno::set_errno(0)`.
This doesn't cover *all* system calls; `rsix` doesn't implement
signal-handling APIs, and this doesn't cover calls made through `std` or
crates like `userfaultfd`, `rand`, and `region`.
This commit moves all of the caching support that currently lives in
`wasmtime-environ` into a `wasmtime-cache` crate and makes it optional. The
goal here is to slim down the `wasmtime-environ` crate and clearly separate
boundaries where caching is a standalone and optional feature, not intertwined
with other crates.
