Remove environment length from HSimulate instructions.

src/hydrogen.cc

Index: src/hydrogen.cc
===================================================================
--- src/hydrogen.cc	(revision 7489)
+++ src/hydrogen.cc	(working copy)
@@ -140,8 +140,7 @@
   int push_count = environment->push_count();
   int pop_count = environment->pop_count();
 
-  int length = environment->length();
-  HSimulate* instr = new HSimulate(id, pop_count, length);
+  HSimulate* instr = new HSimulate(id, pop_count);
   for (int i = push_count - 1; i >= 0; --i) {
     instr->AddPushedValue(environment->ExpressionStackAt(i));
   }