include/guiddef.h: C++ compatibility patch

[Troy Rollo]

On Thu, 1 Sep 2005 14:30, Steven Edwards wrote:

> Well yes some of us do. I work to keep the Wine SDK compatible with
> the PSDK because we have developed a MSVC backend in the ReactOS build
> system and one day (God willing) I will get the ReactOS Project to use
> Wine headers rather than w32api headers. As such it needs to be able
> to compile applications on MSVC and gcc.

OK. I'll submit a version that can deal with this as well after I've tested it 
(should be some time tomorrow).