Method nullify

src/jrd/Record.h:80–89

		}

		void nullify()
		{
			// Zero the record buffer and initialize all fields to NULLs
			const size_t null_bytes = (m_format->fmt_count + 7) >> 3;
			memset(getData(), 0xFF, null_bytes);
			memset(getData() + null_bytes, 0, getLength() - null_bytes);

			// Record has real NULLs now, so clear the "fake-nulls" flag
			m_fake_nulls = false;
		}

		PageStack& getPrecedence()
		{