uucore: for fs use real inode dev stat on wasi

[eduardomourar]

FileInformation previously fell back to a std::fs::Metadata-based heuristic (comparing file type and size) on WASI, since it lacked access to nix::sys::stat. Switch it to rustix::fs::Stat, the same backing type used on Unix, giving WASI real inode/device identity, nlink, and equality checks instead of an approximation. Also add WASI implementations of are_hardlinks_to_same_file and are_hardlinks_or_one_way_symlink_to_same_file via rustix::fs::stat/ lstat, since std::os::unix::fs::MetadataExt is unavailable there.

[codspeed-hq]

Merging this PR will improve performance by 12.39%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 2 improved benchmarks
✅ 343 untouched benchmarks
⏩ 46 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	df_with_path	699.6 µs	570.6 µs	+22.62%
⚡	Simulation	cksum_crc32b	40.9 ms	39.7 ms	+3.03%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing eduardomourar:wasi-fs-inode-dev-stat (ab6642b) with main (bad4676)²}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on main (0c8a3c7) during the generation of this report, so bad4676 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/cut/bounded-memory is now passing!
Congrats! The gnu test tests/tail/pipe-f is now passing!
Note: The gnu test tests/misc/write-errors was skipped on 'main' but is now failing.