[Headers][X86] Use `__builtin_elementwise_ctlz` instead of avx512cd intrinsics.#155089

RKSimon merged 8 commits intollvm:mainllvm/llvm-project:mainfrom

moorabbit:update-avx512cd-lzcntmoorabbit/llvm-project:update-avx512cd-lzcntCopy head branch name to clipboard