paste: simplify 2 loop by while

[oech3]

No description provided.

[codspeed-hq]

Merging this PR will degrade performance by 3.8%

❌ 1 regressed benchmark
✅ 346 untouched benchmarks
⏩ 46 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	cksum_multiple_files	60.6 ms	63 ms	-3.8%

Tip

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

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_{Comparing oech3:paste-loop (e9983fc) with main (a0e62f4)}

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. ↩