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

[Matheus Izvekov via cfe-commits]

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@@ -324,6 +324,8 @@ New Compiler Flags
 
 - New option ``-Wnrvo`` added and disabled by default to warn about missed NRVO opportunities.
 
+- New option ``-ignore-pch`` added to disable precompiled headers, override ``-emit-pch`` and ``-include-pch`` (#GH142409, `PCHDocs <https://clang.llvm.org/docs/UsersManual.html#ignoring-a-pch-file>`_).
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mizvekov wrote:

```suggestion
- New option ``-ignore-pch`` added to disable precompiled headers. It overrides ``-emit-pch`` and ``-include-pch``. (#GH142409, `PCHDocs <https://clang.llvm.org/docs/UsersManual.html#ignoring-a-pch-file>`_).
```

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