* Remove all global state from the caching system This commit is a continuation of an effort to remove usages of `lazy_static!` and similar global state macros which can otherwise be accomodated with passing objects around. Previously there was a global cache system initialized per-process, but it was initialized in a bit of a roundabout way and wasn't actually reachable from the `wasmtime` crate itself. The changes here remove all global state, refactor many of the internals in the cache system, and makes configuration possible through the `wasmtime` crate. Specifically some changes here are: * Usage of `lazy_static!` and many `static` items in the cache module have all been removed. * Global `cache_config()`, `worker()`, and `init()` functions have all been removed. Instead a `CacheConfig` is a "root object" which internally owns its worker and passing around the `CacheConfig` is required for cache usage. * The `wasmtime::Config` structure has grown options to load and parse cache files at runtime. Currently only loading files is supported, although we can likely eventually support programmatically configuring APIs as well. * Usage of the `spin` crate has been removed and the dependency is removed. * The internal `errors` field of `CacheConfig` is removed, instead changing all relevant methods to return a `Result<()>` instead of storing errors internally. * Tests have all been updated with the new interfaces and APIs. Functionally no real change is intended here. Usage of the `wasmtime` CLI, for example, should still enable the cache by default. * Fix lightbeam compilation
This is the wasmtime-jit crate, which contains JIT-based execution
for wasm, using the wasm ABI defined by wasmtime-environ and the
runtime support provided by wasmtime-runtime.