This commit makes a few changes related to recursive reentrance checks, instance
poisoning, etc.:

- Implements the more restrictive lift/lower rules described in WebAssembly/component-model#589 such that a component instance may not lower a function lifted by one of its ancestors, nor vice-versa.  Any such lower will result in a fused adapter which traps unconditionally, preventing guest-to-guest recursive reentrance without requiring data flow analysis.
    - Note that this required updating several WAST tests which were violating the new rule, including some in the `tests/component-model` Git submodule, which I've updated.
    - This is handled entirely in the `fact` module now; I've removed the `AlwaysTrap` case previously handled by `wasmtime-cranelift`.
- Removes `FLAG_MAY_ENTER` from `InstanceFlags`.  It is no longer needed for guest-to-guest calls due to the above, and for guest-to-host-to-guest calls we can rely on either `FLAG_NEEDS_POST_RETURN` for sync-lifted functions or the `GuestTask` call stack for async-lifted functions.
- Adds a `StoreOpaque::trapped` field which is set when _any_ instance belonging to that store traps, at which point the entire store is considered poisoned, meaning no instance belonging to it may be entered.  This prevents indeterminant concurrent task state left over from the trapping instance from leaking into other instances.

Note that this does _not_ include code to push and pop `GuestTask` instances for
guest-to-guest sync-to-sync calls, nor for host-to-guest calls using e.g. the
synchronous `Func::call` API, so certain intrinsics which expect a `GuestTask`
to be present such as `backpressure.inc` will still fail in such cases.  I'll
address that in a later PR.

Also note that I made a small change to `wasmtime-wit-bindgen`, adding a `Send`
bound on the `T` type parameter for `store | async` functions.  This allowed me
to recursively call `{Typed}Func::call_concurrent` from inside a host function,
and it doesn't have any downsides AFAICT.

Fixes bytecodealliance#12128

...and add const assertions to `trap.rs` to help avoid future divergence.