[clang] [clang-cl] Accept `cl`-style output arguments (`/Fo`, `-Fo`) for `--precompile` (PR #121046)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> Is `-Fo` even relevant here? The BMI output name comes from `-ifcOutput` (or `-fmodule-output=`). Consumption of external modules doesn't need an object, so it would only use `-fmodule-output=`.
> 
> > Sorry, I don't remember seeing that discussion
> 
> See this thread: https://discourse.llvm.org/t/clang-cl-exe-support-for-c-modules/72257

But if we want to generate BMI only instead of obj files, we should use `--precompile -o`

https://github.com/llvm/llvm-project/pull/121046