Add ArrayRef constructor from None, and do the cleanups that this constructor enables

Patch by Robert Wilhelm.

llvm-svn: 181138
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 5e30c25..15235c8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5252,7 +5252,7 @@
 MachineSDNode *
 SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT) {
   SDVTList VTs = getVTList(VT);
-  return getMachineNode(Opcode, dl, VTs, ArrayRef<SDValue>());
+  return getMachineNode(Opcode, dl, VTs, None);
 }
 
 MachineSDNode *
@@ -5288,7 +5288,7 @@
 MachineSDNode *
 SelectionDAG::getMachineNode(unsigned Opcode, DebugLoc dl, EVT VT1, EVT VT2) {
   SDVTList VTs = getVTList(VT1, VT2);
-  return getMachineNode(Opcode, dl, VTs, ArrayRef<SDValue>());
+  return getMachineNode(Opcode, dl, VTs, None);
 }
 
 MachineSDNode *
diff --git a/llvm/lib/CodeGen/ShrinkWrapping.cpp b/llvm/lib/CodeGen/ShrinkWrapping.cpp
index 9ab4918..2feea59c 100644
--- a/llvm/lib/CodeGen/ShrinkWrapping.cpp
+++ b/llvm/lib/CodeGen/ShrinkWrapping.cpp
@@ -70,14 +70,14 @@
 
 // Debugging level for shrink wrapping.
 enum ShrinkWrapDebugLevel {
-  None, BasicInfo, Iterations, Details
+  Disabled, BasicInfo, Iterations, Details
 };
 
 static cl::opt<enum ShrinkWrapDebugLevel>
 ShrinkWrapDebugging("shrink-wrap-dbg", cl::Hidden,
   cl::desc("Print shrink wrapping debugging information"),
   cl::values(
-    clEnumVal(None      , "disable debug output"),
+    clEnumVal(Disabled  , "disable debug output"),
     clEnumVal(BasicInfo , "print basic DF sets"),
     clEnumVal(Iterations, "print SR sets for each iteration"),
     clEnumVal(Details   , "print all DF sets"),