[turbofan] Unify referencing of stack slots

src/compiler/frame.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/frame.h"
+
+#include "src/compiler/linkage.h"
+#include "src/compiler/register-allocator.h"
+#include "src/macro-assembler.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+Frame::Frame(int fixed_frame_size_in_slots)
+    : frame_slot_count_(fixed_frame_size_in_slots),
+      spilled_callee_register_slot_count_(0),
+      stack_slot_count_(0),
+      allocated_registers_(NULL),
+      allocated_double_registers_(NULL) {}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8