[libc-commits] [libc] [libc] memmove optimizations (PR #70043)

[Dmitry Vyukov via libc-commits]

dvyukov wrote:

Moved the benchmarks change to #70302.
And I am going to squash the 2 remaining memmove changes into 1 for now.

https://github.com/llvm/llvm-project/pull/70043