Cleanup of deoptimization environment copying functions.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 6683 matching lines @@
               intptr_t deopt_id,
               const Function& function,
               Environment* outer)
       : values_(length),
         locations_(NULL),
         fixed_parameter_count_(fixed_parameter_count),
         deopt_id_(deopt_id),
         function_(function),
         outer_(outer) { }
 
-  // Deep copy the environment.  A 'length' parameter can be given, which
-  // may be less than the environment's length in order to drop values
+  // Deep copy a non-NULL environment.  A 'length' parameter can be given,

[srdjan, 2013/08/22 15:45:31]

This may be redundant information as non-NULL is self understood (all methods in
Dart VM expect the receiver to be non-NULL, don't they?). 

[Kevin Millikin (Google), 2013/08/26 08:59:11]

OK, removed.

+  // which may be less than the environment's length in order to drop values
   // (e.g., passed arguments) from the copy.
-  Environment* DeepCopy() const;
+  Environment* DeepCopy() const { return DeepCopy(Length()); }
   Environment* DeepCopy(intptr_t length) const;
 
   GrowableArray<Value*> values_;
   Location* locations_;
   const intptr_t fixed_parameter_count_;
   intptr_t deopt_id_;
   const Function& function_;
   Environment* outer_;
 
   DISALLOW_COPY_AND_ASSIGN(Environment);
@@ skipping 30 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_