Linearize the graph before creating live ranges.

Change-Id: I02eb5671e3304ab062286131745c1366448aff58
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 27b87ca..1085c10 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -445,7 +445,7 @@
   bool HasUses() const { return uses_ != nullptr || env_uses_ != nullptr; }
 
   size_t NumberOfUses() const {
-    // TODO: Optimize this method if it is used outside of the HGraphTracer.
+    // TODO: Optimize this method if it is used outside of the HGraphVisualizer.
     size_t result = 0;
     HUseListNode<HInstruction>* current = uses_;
     while (current != nullptr) {