Removed loop depth info tracking at graph build time.

runtime/vm/compiler.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
@@ skipping 132 matching lines @@
             FLAG_deoptimization_counter_threshold) {
           const Code& unoptimized_code =
               Code::Handle(parsed_function.function().unoptimized_code());
           isolate->set_ic_data_array(
               unoptimized_code.ExtractTypeFeedbackArray());
         }
       }
 
       // Build the flow graph.
       FlowGraphBuilder builder(parsed_function, NULL);  // NULL = not inlining.
-      flow_graph = builder.BuildGraph(0);  // The initial loop depth is zero.
+      flow_graph = builder.BuildGraph();
     }
 
     if (optimized) {
       TimerScope timer(FLAG_compiler_stats,
                        &CompilerStats::ssa_timer,
                        isolate);
       // Transform to SSA (virtual register 0 and no inlining arguments).
       flow_graph->ComputeSSA(0, NULL);
     }
 
@@ skipping 478 matching lines @@
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart