sort: implement locale aware sort + document the impact on the performances

[sylvestre]

No description provided.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/stdbuf (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[codspeed-hq]

CodSpeed Performance Report

Merging #8752 will degrade performances by 86.45%

_{Comparing sylvestre:sort-perf (b263838) with main (909da50)}

Summary

❌ 18 regressions
✅ 88 untouched
⏩ 73 skipped¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	sort_accented_data[500000]	831.2 ms	1,518.3 ms	-45.25%
❌	sort_ascii_only[500000]	809.3 ms	1,483.1 ms	-45.43%
❌	sort_case_insensitive[500000]	427.8 ms	440.9 ms	-2.97%
❌	sort_case_sensitive[500000]	337.7 ms	564 ms	-40.12%
❌	sort_dictionary_order[500000]	1.1 s	1.1 s	-2.72%
❌	sort_key_field[500000]	699.8 ms	1,114.5 ms	-37.21%
❌	sort_mixed_data[500000]	739.1 ms	1,342.8 ms	-44.96%
❌	sort_reverse_locale[500000]	830.1 ms	1,521 ms	-45.43%
❌	sort_unique_locale[500000]	1.2 s	2.2 s	-46.7%
❌	sort_ascii_c_locale	29.8 ms	91.2 ms	-67.39%
❌	sort_ascii_utf8_locale	59.6 ms	182.5 ms	-67.37%
❌	sort_german_c_locale	95.5 ms	704.8 ms	-86.45%
❌	sort_german_locale	95.5 ms	704.8 ms	-86.45%
❌	sort_mixed_c_locale	95.1 ms	622.9 ms	-84.74%
❌	sort_mixed_utf8_locale	95.1 ms	622.9 ms	-84.74%
❌	sort_random_strings	56.2 ms	225 ms	-75.01%
❌	sort_reverse_mixed	94.2 ms	630.8 ms	-85.06%
❌	sort_unique_mixed	88.6 ms	541.9 ms	-83.65%

Footnotes

1. 73 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. ↩

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/sort/sort-rand. tests/sort/sort-rand is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/tail/overlay-headers (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/sort/sort-rand. tests/sort/sort-rand is passing on 'main'. Maybe you have to rebase?