Add explicit keywords.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53179 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 34f6cb9..37d647b 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -44,7 +44,7 @@
   const ARMSubtarget *Subtarget;
 
 public:
-  ARMDAGToDAGISel(ARMTargetMachine &TM)
+  explicit ARMDAGToDAGISel(ARMTargetMachine &TM)
     : SelectionDAGISel(Lowering), Lowering(TM),
     Subtarget(&TM.getSubtarget<ARMSubtarget>()) {
   }