llvm-project

97732a4d - [libc++][format] Adds print benchmarks.

[libc++][format] Adds print benchmarks. P3107R5 "Permit an efficient implementation of std::print" should improve the performance of std::print. Before implementing these improvements it adds the benchmark provided in the paper. It replaces the `fmt::memory_buffer` with `std::vector<char>`, which is not a stack buffer. However there is not a good Standard type. (std::inplace_vector would be a better type.)