Implement the Microsoft __is_convertible_to type trait, modeling the
semantics after the C++0x is_convertible type trait. This
implementation is not 100% complete, because it allows access errors
to be hard errors (rather than just evaluating false).

Original patch by Steven Watanabe!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124425 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 5a16729..e769eca 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -1828,6 +1828,7 @@
   default: llvm_unreachable("Not a known binary type trait");
   case tok::kw___is_base_of:                 return BTT_IsBaseOf;
   case tok::kw___builtin_types_compatible_p: return BTT_TypeCompatible;
+  case tok::kw___is_convertible_to:          return BTT_IsConvertibleTo;
   }
 }