Simplify virtual frame by removing the virtual stack pointer, which...

src/virtual-frame-ia32.h

Index: src/virtual-frame-ia32.h
===================================================================
--- src/virtual-frame-ia32.h	(revision 766)
+++ src/virtual-frame-ia32.h	(working copy)
@@ -68,7 +68,7 @@
 
   // The height of the virtual expression stack.
   int height() const {
-    return virtual_stack_pointer_ - expression_base_index() + 1;
+    return elements_.length() - expression_base_index();
   }
 
   // Add extra in-memory elements to the top of the frame without generating
@@ -179,14 +179,11 @@
 
   List<Element> elements_;
 
-  // The virtual stack pointer is the index of the top element of the stack.
-  int virtual_stack_pointer_;
-
-  int virtual_frame_pointer_;
-
   int parameter_count_;
   int local_count_;
 
+  int frame_pointer_;
+
   // The index of the first parameter.  The receiver lies below the first
   // parameter.
   int param0_index() const { return 1; }
@@ -198,16 +195,6 @@
 
   // The index of the base of the expression stack.
   int expression_base_index() const { return local0_index() + local_count_; }
-
-  void AddElement(const Element& element) {
-    virtual_stack_pointer_++;
-    elements_.Add(element);
-  }
-
-  Element RemoveElement() {
-    virtual_stack_pointer_--;
-    return elements_.RemoveLast();
-  }
 };