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

[Sharadh Rajaraman via cfe-commits]

sharadhr wrote:

I believe the issue can be distilled further.

On the `main` branch, this command outputs `Hello.bmi`, assuming `Hello.cppm` exists and has `export module Hello;`:
```
clang.exe --precompile -x c++-module -o Hello.bmi -c Hello.cppm
```

This command does not:
```
clang-cl.exe --precompile -x c++-module -o Hello.bmi -c Hello.cppm
```

This command also does not:
```
clang-cl.exe --precompile -x c++-module /o Hello.bmi -c Hello.cppm
```

And the only lines where the driver behaviour appears to diverge, is the `if` block in `Driver.cpp`, commented as below:
```cxx
// Output to a user requested destination?
if (AtTopLevel && !isa<DsymutilJobAction>(JA) && !isa<VerifyJobAction>(JA)) {
  ...
}
```

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