Unoptimises IRSB and _add_data_reference's for individual statements or
        for parts of statements (e.g. Store)

        :param pyvex.IRSB irsb: Block to scan for data references
        :param int irsb_addr: Address of block
        :return: None

def _collect_data_references(self, irsb, irsb_addr):
        """
        Unoptimises IRSB and _add_data_reference's for individual statements or
        for parts of statements (e.g. Store)

        :param pyvex.IRSB irsb: Block to scan for data references
        :param int irsb_addr: Address of block
        :return: None
        """

        if irsb.data_refs:
            self._process_irsb_data_refs(irsb)
        elif irsb.statements:
            irsb = self._unoptimize_irsb(irsb)
            # for each statement, collect all constants that are referenced or used.
            self._collect_data_references_by_scanning_stmts(irsb, irsb_addr)