Implement OpenCL event_t as Clang builtin type, including event_t related OpenCL restrictions (OpenCL 1.2 spec 6.9)

llvm-svn: 172973
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 65e630e..926384d 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1886,6 +1886,7 @@
   case BuiltinType::OCLImage2d: Out << "11ocl_image2d"; break;
   case BuiltinType::OCLImage2dArray: Out << "16ocl_image2darray"; break;
   case BuiltinType::OCLImage3d: Out << "11ocl_image3d"; break;
+  case BuiltinType::OCLEvent: Out << "9ocl_event"; break;
   }
 }