Cleanup of deoptimization environment copying functions.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index 644cb99c8471c14976986bf7cbdfda90c3ed077d..88d32b4744404d3b6aa6728fd78d8f30fed290fe 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -6701,10 +6701,10 @@ class Environment : public ZoneAllocated {
         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_;