uucore: Implement QUOTING_STYLE: c-maybe

[RenjiSann]

This PR implements the new quoting style c-maybe added by GNU 9.12.

[codspeed]

Merging this PR will degrade performance by 25.19%

⚠️ 123 benchmarks spent significant time in system calls

System calls cannot be consistently instrumented, so they are not included in the measure, which understates the real cost. Please switch to the Walltime instrument to accurately measure system calls.

Measurement and system calls

• cksum_default
• ls_recursive_deep_tree[(200, 2)]
• du_all_wide_tree[(5000, 500)]
• sort_mixed_utf8_locale
• sort_reverse_utf8_locale
• sort_unique_utf8_locale
• cksum_raw_output
• cksum_crc
• sort_very_long_lines_utf8_locale
• factor_multiple_u64s[2]
• …and 113 more

ℹ️ 1 benchmark has no flame graph

The flamegraph could not be generated because too much time was spent in runtime internals, making the visualization not useful for performance analysis.

• sort_dictionary_order[500000]

⚠️ 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 regressed benchmarks
✅ 399 untouched benchmarks
⏩ 70 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	factor_three_39_bit_primes	300.2 ms	516.8 ms	-41.91%
❌	Simulation	factor_five_38_bit_primes	1.6 s	1.7 s	-3.66%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing RenjiSann:quoting-c-maybe (7463fc9) with main (98f90f2)}

Footnotes

1. 70 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. ↩

[sylvestre]

rustfmt is sad :)
could you please run cargo fmt?

Diff in /home/runner/work/coreutils/coreutils/src/uucore/src/lib/features/quoting_style/c_quoter.rs:140:
         if escaped.is_escaping() {
             self.must_quote = true;
         }
-        self.buffer
-            .extend(escaped.collect::<String>().into_bytes());
+        self.buffer.extend(escaped.collect::<String>().into_bytes());
     }

     fn push_invalid(&mut self, input: &[u8]) {
##[endgroup]
     Removed 0 files
##[endgroup]
##[error]ssh exited with code 1
Post job cleanup.
[command]/usr/bin/git version
git version 2.55.0
Temporarily overriding HOME='/home/runner/work/_temp/0b325b24-3965-46d3-b221-6787b6bc3688' before making global git config changes
Adding repository directory to the temporary git global config as a safe directory
[command]/usr/bin/git config --global --add safe.directory /home/runner/work/coreutils/coreutils

[cakebaker]

Thanks!