[PATCH] Emit Clang version information into .comment section (Clang's part of implementation) [PART 1]

[Rafael Espíndola]

> Clang changes:
> - Added an additional function "EmitVersionIdentMetadata()" to clang/lib/CodeGen/CodeGenModule.cpp. This emits named metadata for the version string. The format of the metadata is:
>
>     !llvm.ident = !{!N}
>     !N = metadata !{metadata !"clang version string"}
>

I agree we should include the version information. Do you expect llvm
to reason about this in any way? If not, it might be better for clang
to just emit a global inline asm with the .ident, no?

Cheers,
Rafael