Removed loop depth info tracking at graph build time.

runtime/vm/flow_graph_builder.h

Index: runtime/vm/flow_graph_builder.h
===================================================================
--- runtime/vm/flow_graph_builder.h	(revision 17406)
+++ runtime/vm/flow_graph_builder.h	(working copy)
@@ -64,7 +64,7 @@
   FlowGraphBuilder(const ParsedFunction& parsed_function,
                    InliningContext* inlining_context);
 
-  FlowGraph* BuildGraph(intptr_t initial_loop_depth);
+  FlowGraph* BuildGraph();
 
   const ParsedFunction& parsed_function() const { return parsed_function_; }
 
@@ -137,13 +137,11 @@
 class EffectGraphVisitor : public AstNodeVisitor {
  public:
   EffectGraphVisitor(FlowGraphBuilder* owner,
-                     intptr_t temp_index,
-                     intptr_t loop_depth)
+                     intptr_t temp_index)
       : owner_(owner),
         temp_index_(temp_index),
         entry_(NULL),
-        exit_(NULL),
-        loop_depth_(loop_depth) { }
+        exit_(NULL) { }
 
 #define DEFINE_VISIT(type, name) virtual void Visit##type(type* node);
   NODE_LIST(DEFINE_VISIT)
@@ -151,7 +149,6 @@
 
   FlowGraphBuilder* owner() const { return owner_; }
   intptr_t temp_index() const { return temp_index_; }
-  intptr_t loop_depth() const { return loop_depth_; }
   Instruction* entry() const { return entry_; }
   Instruction* exit() const { return exit_; }
 
@@ -328,9 +325,6 @@
   // Output parameters.
   Instruction* entry_;
   Instruction* exit_;
-
-  // Internal state.
-  const intptr_t loop_depth_;
 };
 
 
@@ -342,9 +336,8 @@
 class ValueGraphVisitor : public EffectGraphVisitor {
  public:
   ValueGraphVisitor(FlowGraphBuilder* owner,
-                    intptr_t temp_index,
-                    intptr_t loop_depth)
-      : EffectGraphVisitor(owner, temp_index, loop_depth), value_(NULL) { }
+                    intptr_t temp_index)
+      : EffectGraphVisitor(owner, temp_index), value_(NULL) { }
 
   // Visit functions overridden by this class.
   virtual void VisitLiteralNode(LiteralNode* node);
@@ -406,9 +399,8 @@
  public:
   TestGraphVisitor(FlowGraphBuilder* owner,
                    intptr_t temp_index,
-                   intptr_t loop_depth,
                    intptr_t condition_token_pos)
-      : ValueGraphVisitor(owner, temp_index, loop_depth),
+      : ValueGraphVisitor(owner, temp_index),
         true_successor_addresses_(1),
         false_successor_addresses_(1),
         condition_token_pos_(condition_token_pos) { }