[clang] [clang-tools-extra] [clang] Fix LogDiagnosticPrinter.h and ClangTidyPlugin.cpp after 9e306ad4 (PR #141131)

[Kazu Hirata via cfe-commits]

kazutakahirata wrote:

I still see:

```
/usr/local/google/home/kazu/dev/llvm/llvm-project/llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:163:37: error: no member named 'Retain' in 'clang::DiagnosticOptions'
  163 |   static void retain(T *obj) { obj->Retain(); }
      |                                ~~~  ^
```

from `flang/lib/Frontend/TextDiagnosticPrinter.cpp`.


https://github.com/llvm/llvm-project/pull/141131