Use the wasmtime-cranelift for winch component trampolines

[elliottt]

Instead of reimplementing the component trampolines directly in terms of Winch's MacroAssembler trait, reuse wasmtime-cranelift's Compiler implementation to do that heavy lifting.

I had to remove the type parameter from CompiledFunction and make it a boxed dyn Trait to make this work, due to the requirements of Compiler::append_code, and the visibility of ModuleTextBuilder in the crate hierarchy. I think that this refactoring could be pushed further to avoid the need to have the Compiler trait interface produce &dyn Any results for compiled functions, but haven't looked into making changes further than what was needed to get component trampolines working here.

We can push this work further to remove all trampoline generation from the wasmtime-winch crate, however I didn't want to bulk out the diff in this PR with that additional change, as it's not necessary for running components with winch.

[github-actions]

Subscribe to Label Action

cc @saulecabrera

Details

This issue or pull request has been labeled: "winch"

Thus the following users have been cc'd because of the following labels:

• saulecabrera: winch

To subscribe or unsubscribe from this label, edit the .github/subscribe-to-label.json configuration file.

Learn more.

[github-actions]

Subscribe to Label Action

cc @peterhuene

Details

This issue or pull request has been labeled: "wasmtime:api", "wasmtime:config"

Thus the following users have been cc'd because of the following labels:

• peterhuene: wasmtime:api

To subscribe or unsubscribe from this label, edit the .github/subscribe-to-label.json configuration file.

Learn more.

[github-actions]

Label Messager: wasmtime:config

It looks like you are changing Wasmtime's configuration options. Make sure to
complete this check list:

• If you added a new Config method, you wrote extensive documentation for
  it.

  Details

  Our documentation should be of the following form:

  Short, simple summary sentence.
  
  More details. These details can be multiple paragraphs. There should be
  information about not just the method, but its parameters and results as
  well.
  
  Is this method fallible? If so, when can it return an error?
  
  Can this method panic? If so, when does it panic?
  
  # Example
  
  Optional example here.
  

• If you added a new Config method, or modified an existing one, you
  ensured that this configuration is exercised by the fuzz targets.

  Details

  For example, if you expose a new strategy for allocating the next instance
  slot inside the pooling allocator, you should ensure that at least one of our
  fuzz targets exercises that new strategy.

  Often, all that is required of you is to ensure that there is a knob for this
  configuration option in wasmtime_fuzzing::Config (or one
  of its nested structs).

  Rarely, this may require authoring a new fuzz target to specifically test this
  configuration. See our docs on fuzzing for more details.

• If you are enabling a configuration option by default, make sure that it
  has been fuzzed for at least two weeks before turning it on by default.

---

Details

To modify this label's message, edit the .github/label-messager/wasmtime-config.md file.

To add new label messages or remove existing label messages, edit the
.github/label-messager.json configuration file.

Learn more.