Review: idioms, eliminating panics for traps, and fix cargo dep

* Updates

* Add a verification test to CI

* Produce a global-referencing object on stable

* Restrict CI again

…dealliance#7029)

* Rename `Host*` things to avoid name conflicts with bindings.

* Update to the latest resource-enabled wit files.

* Adapting the code to the new bindings.

* Update wasi-http to the resource-enabled wit deps.

* Start adapting the wasi-http code to the new bindings.

* Make `get_directories` always return new owned handles.

* Simplify the `poll_one` implementation.

* Update the wasi-preview1-component-adapter.

FIXME: temporarily disable wasi-http tests.

Add logging to the cli world, since stderr is now a reseource that
can only be claimed once.

* Work around a bug hit by poll-list, fix a bug in poll-one.

* Comment out `test_fd_readwrite_invalid_fd`, which panics now.

* Fix a few FIXMEs.

* Use `.as_ref().trapping_unwrap()` instead of `TrappingUnwrapRef`.

* Use `drop_in_place`.

* Remove `State::with_mut`.

* Remove the `RefCell` around the `State`.

* Update to wit-bindgen 0.12.

* Update wasi-http to use resources for poll and I/O.

This required making incoming-body and outgoing-body resourrces too, to
work with `push_input_stream_child` and `push_output_stream_child`.

* Re-enable disabled tests, remove logging from the worlds.

* Remove the `poll_list` workarounds that are no longer needed.

* Remove logging from the adapter.

That said, there is no replacement yet, so add a FIXME comment.

* Reenable a test that now passes.

* Remove `.descriptors_mut` and use `with_descriptors_mut` instead.

Replace `.descriptors()` and `.descriptors_mut()` with functions
that take closures, which limits their scope, to prevent them from
invalid aliasing.

* Implement dynamic borrow checking for descriptors.

* Add a cargo-vet audit for wasmtime-wmemcheck.

* Update cargo vet for wit-bindgen 0.12.

* Cut down on duplicate sync/async resource types (#1)

* Allow calling `get-directories` more than once (#2)

For now `Clone` the directories into new descriptor slots as needed.

* Start to lift restriction of stdio only once  (#3)

* Start to lift restriction of stdio only once

This commit adds new `{Stdin,Stdout}Stream` traits which take over the
job of the stdio streams in `WasiCtxBuilder` and `WasiCtx`. These traits
bake in the ability to create a stream at any time to satisfy the API
of `wasi:cli`. The TTY functionality is folded into them as while I was
at it.

The implementation for stdin is relatively trivial since the stdin
implementation already handles multiple streams reading it. Built-in
impls of the `StdinStream` trait are also provided for helper types in
`preview2::pipe` which resulted in the implementation of
`MemoryInputPipe` being updated to support `Clone` where all clones read
the same original data.

* Get tests building

* Un-ignore now-passing test

* Remove unneeded argument from `WasiCtxBuilder::build`

* Fix tests

* Remove some workarounds

Stdio functions can now be called multiple times.

* If `poll_oneoff` fails part-way through, clean up properly.

Fix the `Drop` implementation for pollables to only drop the pollables
that have been successfully added to the list.

This fixes the poll_oneoff_files failure and removes a FIXME.

---------

Co-authored-by: Alex Crichton <alex@alexcrichton.com>

…dealliance#7029)

* Rename `Host*` things to avoid name conflicts with bindings.

* Update to the latest resource-enabled wit files.

* Adapting the code to the new bindings.

* Update wasi-http to the resource-enabled wit deps.

* Start adapting the wasi-http code to the new bindings.

* Make `get_directories` always return new owned handles.

* Simplify the `poll_one` implementation.

* Update the wasi-preview1-component-adapter.

FIXME: temporarily disable wasi-http tests.

Add logging to the cli world, since stderr is now a reseource that
can only be claimed once.

* Work around a bug hit by poll-list, fix a bug in poll-one.

* Comment out `test_fd_readwrite_invalid_fd`, which panics now.

* Fix a few FIXMEs.

* Use `.as_ref().trapping_unwrap()` instead of `TrappingUnwrapRef`.

* Use `drop_in_place`.

* Remove `State::with_mut`.

* Remove the `RefCell` around the `State`.

* Update to wit-bindgen 0.12.

* Update wasi-http to use resources for poll and I/O.

This required making incoming-body and outgoing-body resourrces too, to
work with `push_input_stream_child` and `push_output_stream_child`.

* Re-enable disabled tests, remove logging from the worlds.

* Remove the `poll_list` workarounds that are no longer needed.

* Remove logging from the adapter.

That said, there is no replacement yet, so add a FIXME comment.

* Reenable a test that now passes.

* Remove `.descriptors_mut` and use `with_descriptors_mut` instead.

Replace `.descriptors()` and `.descriptors_mut()` with functions
that take closures, which limits their scope, to prevent them from
invalid aliasing.

* Implement dynamic borrow checking for descriptors.

* Add a cargo-vet audit for wasmtime-wmemcheck.

* Update cargo vet for wit-bindgen 0.12.

* Cut down on duplicate sync/async resource types (#1)

* Allow calling `get-directories` more than once (#2)

For now `Clone` the directories into new descriptor slots as needed.

* Start to lift restriction of stdio only once  (#3)

* Start to lift restriction of stdio only once

This commit adds new `{Stdin,Stdout}Stream` traits which take over the
job of the stdio streams in `WasiCtxBuilder` and `WasiCtx`. These traits
bake in the ability to create a stream at any time to satisfy the API
of `wasi:cli`. The TTY functionality is folded into them as while I was
at it.

The implementation for stdin is relatively trivial since the stdin
implementation already handles multiple streams reading it. Built-in
impls of the `StdinStream` trait are also provided for helper types in
`preview2::pipe` which resulted in the implementation of
`MemoryInputPipe` being updated to support `Clone` where all clones read
the same original data.

* Get tests building

* Un-ignore now-passing test

* Remove unneeded argument from `WasiCtxBuilder::build`

* Fix tests

* Remove some workarounds

Stdio functions can now be called multiple times.

* If `poll_oneoff` fails part-way through, clean up properly.

Fix the `Drop` implementation for pollables to only drop the pollables
that have been successfully added to the list.

This fixes the poll_oneoff_files failure and removes a FIXME.

---------

Co-authored-by: Alex Crichton <alex@alexcrichton.com>

* Debugging: add builtin gdbstub component.

This adds a debug component that makes use of the debug-main world
defined in bytecodealliance#12756 and serves the gdbstub protocol, with Wasm
extensions, compatible with LLDB.

This component is built and included inside the Wasmtime binary, and
is loaded using the lower-level `-D debugger=...` debug-main option;
the user doesn't need to specify the `.wasm` adapter
component. Instead, the user simply runs `wasmtime run -g <PORT>
program.wasm ...` and Wasmtime will load and prepare to run
`program.wasm` as the debuggee, waiting for a gdbstub connection on
the given TCP port before continuing.

The workflow is:

```
$ wasmtime run -g 1234 program.wasm
[ wasmtime starts and waits for connection ]

$ /opt/wasi-sdk/bin/lldb  # use LLDB from wasi-sdk release 32 or later
(lldb) process connect --plugin wasm connect://localhost:1234
Process 1 stopped
* thread #1, stop reason = signal SIGTRAP
    frame #0: 0x40000000000001cc
->  0x40000000000001cc: unreachable
    0x40000000000001cd: end
    0x40000000000001ce: local.get 0
    0x40000000000001d0: call   13
(lldb) si
Process 1 stopped
* thread #1, stop reason = instruction step into
    frame #0: 0x4000000000000184
->  0x4000000000000184: block
    0x4000000000000186: block
    0x4000000000000188: global.get 1
    0x400000000000018e: i32.const 3664
[ ... ]
```

This makes use of the `gdbstub` third-party crate, into which I've
upstreamed support for the Wasm extensions in daniel5151/gdbstub#188,
daniel5151/gdbstub#189, daniel5151/gdbstub#190, and
daniel5151/gdbstub#192. (I'll add vets as part of this PR.)

* cargo vets.

* Handle Trap events as well as breakpoints.

* Review feedback.

* Fix gdbstub artifact build to make it publishable (by disabling it when isolated crates are used).

* Review feedback.

* fix published-crates list

* For now, empty gdbstub data but no compile error when artifact crate is published.

* add some more Cargo metadata: version for artifact crate dep