Implement SharedArrayBuffer

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index ec9de6248fcdd32c52fe590e11d77d424c635103..d1b7fface2ea40c6491c33ed366a6a10a100513c 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1127,6 +1127,14 @@ class Isolate {
     return array_buffer_allocator_;
   }
 
+  void set_shared_array_buffer_allocator(
+      v8::ArrayBuffer::Allocator* allocator) {
+    shared_array_buffer_allocator_ = allocator;
+  }
+  v8::ArrayBuffer::Allocator* shared_array_buffer_allocator() {
+    return shared_array_buffer_allocator_;
+  }
+
  protected:
   explicit Isolate(bool enable_serializer);
 
@@ -1356,6 +1364,7 @@ class Isolate {
   List<Object*> partial_snapshot_cache_;
 
   v8::ArrayBuffer::Allocator* array_buffer_allocator_;
+  v8::ArrayBuffer::Allocator* shared_array_buffer_allocator_;
 
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;