Add the Microsoft __is_interface_class type trait.
Patch by Andy Gibbs!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164591 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseTentative.cpp b/lib/Parse/ParseTentative.cpp
index 01ab0e4..40c4eee 100644
--- a/lib/Parse/ParseTentative.cpp
+++ b/lib/Parse/ParseTentative.cpp
@@ -782,6 +782,7 @@
   case tok::kw___is_convertible_to:
   case tok::kw___is_empty:
   case tok::kw___is_enum:
+  case tok::kw___is_interface_class:
   case tok::kw___is_final:
   case tok::kw___is_literal:
   case tok::kw___is_literal_type: