llvm-project

42e0cdf2 - [Clang] Implement P2843R3 - Preprocessing is never undefined (#192073)

[Clang] Implement P2843R3 - Preprocessing is never undefined (#192073) This PR marks [P2843R3 - Preprocessing is never undefined](https://wg21.link/P2843) as implemented and add tests. Fixes https://github.com/llvm/llvm-project/issues/145658 --------- Signed-off-by: yronglin <yronglin777@gmail.com>