Add --trace_type_check_elimination flag for debugging purposes.

runtime/vm/code_generator.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/code_generator.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 306 matching lines @@
     cloned_ctx.SetAt(i, Instance::Handle(ctx.At(i)));
   }
   arguments.SetReturn(cloned_ctx);
 }
 
 
 // Helper routine for tracing a type check.
 static void PrintTypeCheck(
     const char* message,
     const Instance& instance,
-    const AbstractType&type,
+    const AbstractType& type,
     const AbstractTypeArguments& instantiator_type_arguments,
     const Bool& result) {
   DartFrameIterator iterator;
   StackFrame* caller_frame = iterator.NextFrame();
   ASSERT(caller_frame != NULL);
 
   const Type& instance_type = Type::Handle(instance.GetType());
   ASSERT(instance_type.IsInstantiated());
   if (type.IsInstantiated()) {
     OS::Print("%s: '%s' %s '%s' (pc: 0x%x).\n",
@@ skipping 1184 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart