cp: reduce memory usage for cp -al by skipping unnecessary tracking

[ChrisDryden]

This test makes sure that in a large folder, the memory usage doesn't go up a bunch in this mode. The change itself to fix this is just to add a if check that if its this mode to not store all of the additional metadata since there's no need to use it later.

[codspeed-hq]

CodSpeed Performance Report

Merging #9805 will degrade performance by 3.06%

_{Comparing ChrisDryden:fix-cp-link-heap-memory (ee0d7e3) with main (585f46a)}

Summary

❌ 1 regression
✅ 126 untouched
⏩ 6 skipped¹

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

Benchmarks breakdown

	Benchmark	BASE	HEAD	Efficiency
❌	tsort_input_parsing_heavy[5000]	82.1 ms	84.7 ms	-3.06%

Footnotes

1. 6 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:

Congrats! The gnu test tests/cp/link-heap is no longer failing!