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

Patch by Robert Wilhelm.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181138 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ShrinkWrapping.cpp b/lib/CodeGen/ShrinkWrapping.cpp
index 9ab4918..2feea59 100644
--- a/lib/CodeGen/ShrinkWrapping.cpp
+++ b/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"),