objects.h splitting: Split out ScopeInfo + add necessary structures.

src/objects/object-macros.h

+// Copyright 2016 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.
+
+// Note 1: Any file that includes this one should include object-macros-undef.h
+// at the bottom.
+
+// Note 2: This file is deliberately missing the include guards (the undeffing
+// approach wouldn't work otherwise).
+
+#define DECL_BOOLEAN_ACCESSORS(name) \
+  inline bool name() const;          \
+  inline void set_##name(bool value);
+
+#define DECL_INT_ACCESSORS(name) \
+  inline int name() const;       \
+  inline void set_##name(int value);
+
+#define DECL_ACCESSORS(name, type)    \
+  inline type* name() const;          \
+  inline void set_##name(type* value, \
+                         WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
+#define DECLARE_CAST(type)                   \
+  INLINE(static type* cast(Object* object)); \
+  INLINE(static const type* cast(const Object* object));