Method getSync

src/jrd/Attachment.h:329–336

	}

	Sync* getSync(bool useAsync = false, bool forceAsync = false)
	{
		if (useAsync && !forceAsync)
		{
			fb_assert(!mainSync.locked());
		}
		return useAsync ? &async : &mainSync;
	}

	Firebird::Mutex* getBlockingMutex()
	{