perf(traverse): get_unique_name use String::set_len

[overlookmotel]

Follow-on after #10562. We had to remove an optimization due to lack of set_len method on String. #10757 adds that method, so now we can use it.

[overlookmotel]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• perf(traverse): get_unique_name use String::set_len #10758 👈 (View in Graphite)
• feat(allocator): add String::set_len method #10757
• main

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #10758 will not alter performance

_{Comparing 05-01-perf_traverse_get_unique_name_use_string_set_len_ (2123607) with 05-01-feat_allocator_add_string_set_len_method (1b4d9ff)}

Summary

✅ 36 untouched benchmarks

[overlookmotel]

Superceded by #10759.