[cfe-commits] [Patch] Fix for r163013 regression and further__interface enhancement

[Andy Gibbs]

Bah, eagle-eyed reviewers will note that this patch also contains the 
implementation for the __is_interface_class type trait that MSVC provides. 
I mistakenly diffed between trunk and branch and forgot to strip this out. 
My apologies -- if its inclusion is a problem, shout and I'll post a new 
patch...

Sorry
Andy