[PATCH][Win] Fix assertion failure when passing 'nul' in input to cc1.

[Rafael Espíndola]

> Good point.
> That #else could be removed.
> I noticed however that in "llvm/Support/Process.h", if the OS is
> neither Windows nor Linux, we #error with "Unsupported operating
> system.".
> Should I add #error in case of unsupported OS or do you prefer that I
> remove the #else entirely?

Just remove it. Anyone porting llvm to a non-win32 non-posix system is
going to have bigger issues :-)

>>
>>
>> While you are at it, would you mind also updating the default constructor?
>
> Sure, I will fix the default constructor.

Thanks.

>>
>>
>> Do we also crash in some llvm tools like llvm-as? That would allow us
>> to test directly from llvm.
>
> Unfortunately I am only able to reproduce the assertion failure with clang..
> I just finished testing llvm-as, llvm-dis, llc and opt; none of those
> tools crash for me.

Yes, the clang test is fine.

Cheers,
Rafael