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

[Ying Yi via cfe-commits]

MaggieYingYi wrote:

Thanks @dyung for helping me verify the possible fixes. Unfortunately, the test would not pass by removing `-E`. Therefore, I had reverted the commit 4fb81f11cea0fce9f1f5409fcd55ae3aba70d368. 

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