[clang] [Clang][Driver] Expose `-fno-eliminate-unused-debug-types` to clang-cl (PR #95259)

[David Blaikie via cfe-commits]

dwblaikie wrote:

I will say, `-fno-eliminate-unused-debug-types` is a really heavy hammer that makes debug info much larger - and my understanding was that games tended to have trouble with large debug builds, so I'd be surprised if this was a great path forward.

Do you have a small example of where Clang and MSVC differ in emitting some particular unreferenced type? I would imagine MSVC isn't emitting /every/ written type... 

https://github.com/llvm/llvm-project/pull/95259