[PATCH} Remove '.bc' input support from the frontend

[Alexey Bataev]

> I've definitely used the feature before and likely will again. That
> said I personally don't mind doing llvm-dis on a bc file before doing
> it.
>
> The main reason to keep some aspect of the functionality: It's the
> only way to be sure you're actually passing a bit of bitcode through
> the precise pipeline that clang has set up.
>
> -eric

We're using this feature often and it would be good to keep it. Alp, it 
would be good to find another solution rather than remove .bc 
compilation support from clang.

Best regards,
Alexey Bataev
=============
Software Engineer
Intel Compiler Team