[clang] [llvm] [clang] Introduce target-specific `Sema` components (PR #93179)

[Vlad Serebrennikov via llvm-commits]

Endilll wrote:

Thank you for letting me know! Given the amount of positive feedback I've heard about this effort, I think we'll continue, trying to claw back the compile times elsewhere (my recent patch that removed try_compile checks from CMake should've helped, even if it's not counted in your metrics).

https://github.com/llvm/llvm-project/pull/93179