[wasm] Add guard regions to end of WebAssembly.Memory buffers

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 10916 matching lines @@
 
   inline bool is_neuterable();
   inline void set_is_neuterable(bool value);
 
   inline bool was_neutered();
   inline void set_was_neutered(bool value);
 
   inline bool is_shared();
   inline void set_is_shared(bool value);
 
+  inline bool has_guard_region();
+  inline void set_has_guard_region(bool value);
+
   DECLARE_CAST(JSArrayBuffer)
 
   void Neuter();
 
   V8_EXPORT_PRIVATE static void Setup(
       Handle<JSArrayBuffer> array_buffer, Isolate* isolate, bool is_external,
       void* data, size_t allocated_length,
       SharedFlag shared = SharedFlag::kNotShared);
 
   static bool SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
@@ skipping 19 matching lines @@
       kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
 
   // Iterates all fields in the object including internal ones except
   // kBackingStoreOffset and kBitFieldSlot.
   class BodyDescriptor;
 
   class IsExternal : public BitField<bool, 1, 1> {};
   class IsNeuterable : public BitField<bool, 2, 1> {};
   class WasNeutered : public BitField<bool, 3, 1> {};
   class IsShared : public BitField<bool, 4, 1> {};
+  class HasGuardRegion : public BitField<bool, 5, 1> {};
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
 };
 
 
 class JSArrayBufferView: public JSObject {
  public:
   // [buffer]: ArrayBuffer that this typed array views.
   DECL_ACCESSORS(buffer, Object)
@@ skipping 798 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_