Checking for stack height equality between full codegen and hydrogen.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 17cb7d1aa156edfc660f1e0ce1236d054d536d35..2f280bd1adab8e6bcf622900588d0c8dbdfa60fd 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -109,17 +109,14 @@ class HBasicBlock V8_FINAL : public ZoneObject {
 
   bool HasParentLoopHeader() const { return parent_loop_header_ != NULL; }
 
-  void SetJoinId(BailoutId ast_id);
+  void SetJoinId(BailoutId ast_id, int stack_checker_offset = 0);
 
   int PredecessorIndexOf(HBasicBlock* predecessor) const;
   HPhi* AddNewPhi(int merged_index);
   HSimulate* AddNewSimulate(BailoutId ast_id,
                             HSourcePosition position,
-                            RemovableSimulate removable = FIXED_SIMULATE) {
-    HSimulate* instr = CreateSimulate(ast_id, removable);
-    AddInstruction(instr, position);
-    return instr;
-  }
+                            RemovableSimulate removable = FIXED_SIMULATE,
+                            int arguments_offset = 0);
   void AssignCommonDominator(HBasicBlock* other);
   void AssignLoopSuccessorDominators();
 
@@ -165,7 +162,8 @@ class HBasicBlock V8_FINAL : public ZoneObject {
  protected:
   friend class HGraphBuilder;
 
-  HSimulate* CreateSimulate(BailoutId ast_id, RemovableSimulate removable);
+  HSimulate* CreateSimulate(BailoutId ast_id, RemovableSimulate removable,
+                            int arguments_offset);
   void Finish(HControlInstruction* last, HSourcePosition position);
   void FinishExit(HControlInstruction* instruction, HSourcePosition position);
   void Goto(HBasicBlock* block,
@@ -703,6 +701,10 @@ class HEnvironment V8_FINAL : public ZoneObject {
 
   Zone* zone() const { return zone_; }
 
+  void VerifyStackHeight(BailoutId ast_id,
+                         int hydrogen_id,
+                         int stack_height_offset = 0);
+
  private:
   HEnvironment(const HEnvironment* other, Zone* zone);
 
@@ -1293,7 +1295,8 @@ class HGraphBuilder {
     return AddInstructionTyped(New<I>(p1, p2, p3, p4, p5, p6, p7, p8));
   }
 
-  void AddSimulate(BailoutId id, RemovableSimulate removable = FIXED_SIMULATE);
+  void AddSimulate(BailoutId id, RemovableSimulate removable = FIXED_SIMULATE,
+                   int arguments_offset = 0);
 
  protected:
   virtual bool BuildGraph() = 0;
@@ -1888,7 +1891,7 @@ template<>
 inline HSimulate* HGraphBuilder::Add<HSimulate>(
     BailoutId id,
     RemovableSimulate removable) {
-  HSimulate* instr = current_block()->CreateSimulate(id, removable);
+  HSimulate* instr = current_block()->CreateSimulate(id, removable, 0);
   AddInstruction(instr);
   return instr;
 }