* Remove unnecessary into_iter/map
Forgotten from a previous refactoring, this variable was already of the
right type!
* Move `wasmtime_jit::Compiler` into `wasmtime`
This `Compiler` struct is mostly a historical artifact at this point and
wasn't necessarily pulling much weight any more. This organization also
doesn't lend itself super well to compiling out `cranelift` when the
`Compiler` here is used for both parallel iteration configuration
settings as well as compilation.
The movement into `wasmtime` is relatively small, with
`Module::build_artifacts` being the main function added here which is a
merging of the previous functions removed from the `wasmtime-jit` crate.
* Add a `cranelift` compile-time feature to `wasmtime`
This commit concludes the saga of refactoring Wasmtime and making
Cranelift an optional dependency by adding a new Cargo feature to the
`wasmtime` crate called `cranelift`, which is enabled by default.
This feature is implemented by having a new cfg for `wasmtime` itself,
`cfg(compiler)`, which is used wherever compilation is necessary. This
bubbles up to disable APIs such as `Module::new`, `Func::new`,
`Engine::precompile_module`, and a number of `Config` methods affecting
compiler configuration. Checks are added to CI that when built in this
mode Wasmtime continues to successfully build. It's hoped that although
this is effectively "sprinkle `#[cfg]` until things compile" this won't
be too too bad to maintain over time since it's also an use case we're
interested in supporting.
With `cranelift` disabled the only way to create a `Module` is with the
`Module::deserialize` method, which requires some form of precompiled
artifact.
Two consequences of this change are:
* `Module::serialize` is also disabled in this mode. The reason for this
is that serialized modules contain ISA/shared flags encoded in them
which were used to produce the compiled code. There's no storage for
this if compilation is disabled. This could probably be re-enabled in
the future if necessary, but it may not end up being all that necessary.
* Deserialized modules are not checked to ensure that their ISA/shared
flags are compatible with the host CPU. This is actually already the
case, though, with normal modules. We'll likely want to fix this in
the future using a shared implementation for both these locations.
Documentation should be updated to indicate that `cranelift` can be
disabled, although it's not really the most prominent documentation
because this is expected to be a somewhat niche use case (albeit
important, just not too common).
* Always enable cranelift for the C API
* Fix doc example builds
* Fix check tests on GitHub Actions