[llvm] [CMake][Windows] Fix Debug config build when using MSBuild (PR #111765)

[NAKAMURA Takumi via llvm-commits]

https://github.com/chapuni commented:

I don't understand your real issue. Could you elaborate?

If you specifies `LLVM_TABLEGEN` with no reasons, I suggest you stopping it.
Do you use `LLVM_OPTIMIZED_TABLEGEN`?

https://github.com/llvm/llvm-project/pull/111765