Replace programs/fileio_asyncio.c with a declaration-only shim and register
Rust's async file-I/O implementation in the library archive. Preserve the C
ABI for pool and job contexts, including DEBUGLEVEL pointer-based pthread
wrappers, and select separate Rust build configurations for those layouts.
Keep ordered-read queue state locked while waiting, drain queued work before
shutdown frees job buffers, and use platform large-file seeks for sparse writes.
Test Plan:
- `cargo test --no-default-features --lib fileio_asyncio` (7 passed).
- `cargo test --no-default-features --features debug-pthread --lib fileio_asyncio` (7 passed).
- `cargo check --all-targets`, clippy library/benches/tests, and nightly fmt check (passed).
- Threaded program build and README round-trip (passed).
- `make -C tests poolTests` and `./tests/poolTests` (passed).
- Current C shim object defines no `AIO_*` symbols; the Rust archive exports all 20 declarations.
- Full standalone all-target Rust tests and the default CLI archive rebuild remain affected by unrelated C/Rust integration and another worker's in-progress benchmark changes.
Fixes a bug in AsyncIO where we queue reads after opening a file so our queue will always be saturated (or as saturated as possible).
Previous code was looping up to `availableJobsCount` not realizing `availableJobsCount` was also decreasing in each iteration, so instead of queueing 10 jobs we'd queue 5 (and instead of 2 we'd queue 1).
This PR fixes the loop to queue as long as `availableJobsCount` is not 0.
```
for f in $(find . \( -path ./.git -o -path ./tests/fuzz/corpora \) -prune -o -type f);
do
sed -i 's/Facebook, Inc\./Meta Platforms, Inc. and affiliates./' $f;
done
```
* Refactored fileio.c:
- Extracted asyncio code to fileio_asyncio.c/.h
- Moved type definitions to fileio_types.h
- Moved common macro definitions needed by both fileio.c and fileio_asyncio.c to fileio_common.h
* Bugfix - rename fileio_asycio to fileio_asyncio
* Added copyrights & license to new files
* CR fixes
ddidderr
Yann Collet