* func_wrap_async typechecks
* func call async
* instantiate_async
* fixes
* async engine creation for tests
* start adding a component model test for async
* fix wrong check for async support, factor out Instance::new_started to an unchecked impl
* tests: wibbles
* component::Linker::func_wrap: replace IntoComponentFunc with directly accepting a closure
We find that this makes the Linker::func_wrap type signature much easier
to read. The IntoComponentFunc abstraction was adding a lot of weight to
"splat" a set of arguments from a tuple of types into individual
arguments to the closure. Additionally, making the StoreContextMut
argument optional, or the Result<return> optional, wasn't very
worthwhile.
* Fixes for the new style of closure required by component::Linker::func_wrap
* future of result of return
* add Linker::instantiate_async and {Typed}Func::post_return_async
* fix fuzzing generator
* note optimisation opportunity
* simplify test
12e4a1ba18