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/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index fb0c4d2..2cd7f04 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -5357,6 +5357,7 @@
   case CK_IntegralRealToComplex:
   case CK_IntegralComplexCast:
   case CK_IntegralComplexToFloatingComplex:
+  case CK_BuiltinFnToFnPtr:
     llvm_unreachable("invalid cast kind for integral value");
 
   case CK_BitCast:
@@ -5843,6 +5844,7 @@
   case CK_ARCReclaimReturnedObject:
   case CK_ARCExtendBlockObject:
   case CK_CopyAndAutoreleaseBlockObject:
+  case CK_BuiltinFnToFnPtr:
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_LValueToRValue: