Subzero: Improve debugging controls, plus minor refactoring.

src/IceLiveness.cpp

Index: src/IceLiveness.cpp
diff --git a/src/IceLiveness.cpp b/src/IceLiveness.cpp
index 79578a5200ee1c8294fd2b65a99effb6f0e4e9bf..f16eb846b5a8f4efdf2c8f2a423f1a35dc8b1ce1 100644
--- a/src/IceLiveness.cpp
+++ b/src/IceLiveness.cpp
@@ -77,10 +77,8 @@ void Liveness::init() {
   assert(NumGlobals == TmpNumGlobals);
 
   // Process each node.
-  const NodeList &LNodes = Func->getNodes();
-  SizeT NumLNodes = LNodes.size();
-  for (SizeT i = 0; i < NumLNodes; ++i) {
-    LivenessNode &Node = Nodes[LNodes[i]->getIndex()];
+  for (const CfgNode *LNode : Func->getNodes()) {
+    LivenessNode &Node = Nodes[LNode->getIndex()];
     // NumLocals, LiveToVarMap already initialized
     Node.LiveIn.resize(NumGlobals);
     Node.LiveOut.resize(NumGlobals);