Change the representation of builtin functions in the AST
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call.  Fixes PR13195.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162962 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTCommon.cpp b/lib/Serialization/ASTCommon.cpp
index 67f74f7..0ec03cf 100644
--- a/lib/Serialization/ASTCommon.cpp
+++ b/lib/Serialization/ASTCommon.cpp
@@ -60,6 +60,9 @@
   case BuiltinType::ObjCId:     ID = PREDEF_TYPE_OBJC_ID;       break;
   case BuiltinType::ObjCClass:  ID = PREDEF_TYPE_OBJC_CLASS;    break;
   case BuiltinType::ObjCSel:    ID = PREDEF_TYPE_OBJC_SEL;      break;
+  case BuiltinType::BuiltinFn:
+                                ID = PREDEF_TYPE_BUILTIN_FN; break;
+
   }
 
   return TypeIdx(ID);