Improved MSVC __interface support by adding first class support for it, instead of aliasing to "struct" which had some incorrect behaviour. Patch by David Robins.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163013 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateVariadic.cpp b/lib/Sema/SemaTemplateVariadic.cpp
index aece90b..6147d63 100644
--- a/lib/Sema/SemaTemplateVariadic.cpp
+++ b/lib/Sema/SemaTemplateVariadic.cpp
@@ -727,6 +727,7 @@
   case TST_enum:
   case TST_union:
   case TST_struct:
+  case TST_interface:
   case TST_class:
   case TST_auto:
   case TST_unknown_anytype: