Enable warnings if `cranelift` is disabled (#10157)

Continuation of work in #10131.

Add support for `#![no_std]` to the `wasmtime` crate (#8533)

* Always fall back to custom platform for Wasmtime

This commit updates Wasmtime's platform support to no longer require an
opt-in `RUSTF

Add support for `#![no_std]` to the `wasmtime` crate (#8533)

* Always fall back to custom platform for Wasmtime

This commit updates Wasmtime's platform support to no longer require an
opt-in `RUSTFLAGS` `--cfg` flag to be specified. With `no_std` becoming
officially supported this should provide a better onboarding experience
where the fallback custom platform is used. This will cause linker
errors if the symbols aren't implemented and searching/googling should
lead back to our docs/repo (eventually, hopefully).

* Change Wasmtime's TLS state to a single pointer

This commit updates the management of TLS to rely on just a single
pointer rather than a pair of a pointer and a `bool`. Additionally
management of the TLS state is pushed into platform-specific modules to
enable different means of managing it, namely the "custom" platform now
has a C function required to implement TLS state for Wasmtime.

* Delay conversion to `Instant` in atomic intrinsics

The `Duration` type is available in `no_std` but the `Instant` type is
not. The intention is to only support the `threads` proposal if `std` is
active but to assist with this split push the `Duration` further into
Wasmtime to avoid using a type that can't be mentioned in `no_std`.

* Gate more parts of Wasmtime on the `profiling` feature

Move `serde_json` to an optional dependency and gate the guest profiler
entirely on the `profiling` feature.

* Refactor conversion to `anyhow::Error` in `wasmtime-environ`

Have a dedicated trait for consuming `self` in addition to a
`Result`-friendly trait.

* Gate `gimli` in Wasmtime on `addr2line`

Cut down the dependency list if `addr2line` isn't enabled since then
the dependency is not used. While here additionally lift the version
requirement for `addr2line` up to the workspace level.

* Update `bindgen!` to have `no_std`-compatible output

Pull most types from Wasmtime's `__internal` module as the source of
truth.

* Use an `Option` for `gc_store` instead of `OnceCell`

No need for synchronization here when mutability is already available in
the necessary contexts.

* Enable embedder-defined host feature detection

* Add `#![no_std]` support to the `wasmtime` crate

This commit enables compiling the `runtime`, `gc`, and `component-model`
features of the `wasmtime` crate on targets that do not have `std`. This
tags the crate as `#![no_std]` and then updates everything internally to
import from `core` or `alloc` and adapt for the various idioms. This
ended up requiring some relatively extensive changes, but nothing too
too bad in the grand scheme of things.

* Require `std` for the perfmap profiling agent

prtest:full

* Fix build on wasm

* Fix windows build

* Remove unused import

* Fix Windows/Unix build without `std` feature

* Fix some doc links

* Remove unused import

* Fix build of wasi-common in isolation

* Fix no_std build on macos

* Re-fix build

* Fix standalone build of wasmtime-cli-flags

* Resolve a merge conflict

* Review comments

* Remove unused import

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