[clang] [Frontend][PCH]-Add support for ignoring PCH options (-ignore-pch). (PR #142409)

[Ying Yi via cfe-commits]

MaggieYingYi wrote:

I can see the test `Clang::crash-vfs-include-pch.m` using -E when including a pch file. This PR applied the following change: if command is prepossess (`-E`), `-include-pch` is ignored. This caused the test failure. I think the `-E` needs to be removed in the command line. However, I cannot reproduce the error. The test is unsupported. I am still trying to reproduce the error locally.

https://github.com/llvm/llvm-project/pull/142409