Revert of More simplification and unification of frame handling

src/crankshaft/lithium.h

Index: src/crankshaft/lithium.h
diff --git a/src/crankshaft/lithium.h b/src/crankshaft/lithium.h
index 5cfc0c358a064adae71f6fc87d702e48b887b4be..10e980e9836006e67a8d18e88cece08a9ddaf34d 100644
--- a/src/crankshaft/lithium.h
+++ b/src/crankshaft/lithium.h
@@ -638,13 +638,7 @@
 
   int ParameterAt(int index);
   int GetParameterStackSlot(int index) const;
-  bool HasAllocatedStackSlots() const {
-    return current_frame_slots_ != base_frame_slots_;
-  }
-  int GetSpillSlotCount() const {
-    return current_frame_slots_ - base_frame_slots_;
-  }
-  int GetTotalFrameSlotCount() const { return current_frame_slots_; }
+  int spill_slot_count() const { return spill_slot_count_; }
   CompilationInfo* info() const { return info_; }
   HGraph* graph() const { return graph_; }
   Isolate* isolate() const { return graph_->isolate(); }
@@ -693,8 +687,7 @@
  protected:
   LChunk(CompilationInfo* info, HGraph* graph);
 
-  int base_frame_slots_;
-  int current_frame_slots_;
+  int spill_slot_count_;
 
  private:
   void CommitDependencies(Handle<Code> code) const;
@@ -764,6 +757,8 @@
 };
 
 
+int StackSlotOffset(int index);
+
 enum NumberUntagDMode {
   NUMBER_CANDIDATE_IS_SMI,
   NUMBER_CANDIDATE_IS_ANY_TAGGED