[libcxx-commits] [libcxx] [libc++] Fix append_range and prepend_range benchmarks (PR #216038)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 approved this pull request.

Do we also want a `(with reserve)` version?

https://github.com/llvm/llvm-project/pull/216038