add missing atomic intrinsic from gcc

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52270 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index f1dc64d..a55f904 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -3526,6 +3526,8 @@
     return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_OR);
   case Intrinsic::atomic_load_xor:
     return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_XOR);
+  case Intrinsic::atomic_load_nand:
+    return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_NAND);
   case Intrinsic::atomic_load_min:
     return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_MIN);
   case Intrinsic::atomic_load_max: