[clang] [clang-tools-extra] [lldb] [clang] Remove intrusive reference count from `DiagnosticOptions` (PR #139584)

[Kazu Hirata via cfe-commits]

kazutakahirata wrote:

> Thanks, I'll fix those ASAP.

@jansvoboda11 Please feel free to add me as a reviewer.  I am happy to build things with your fix.


https://github.com/llvm/llvm-project/pull/139584