[clang] Prefer clang_setup over use_clang

This patch switches over uses of use_clang to clang_setup to fix a
potential race condition that has been impacting CI.

This is split from the refactoring to ensure I'm not missing anything
major here on the clang-tools-extra side.

This should fix #145703.

Reviewers: AaronBallman, HighCommander4, HerrCai0907, petrhosek, Keenuts

Reviewed By: petrhosek

Pull Request: https://github.com/llvm/llvm-project/pull/147437

GitOrigin-RevId: 896575eb74bb59466b50fb51934596d72947ebd5
2 files changed