As part of parse_line(), checks for new executable declarations in the statement.

def _rt_parse_execs(self, statement, element, mode, lineparser):
        """As part of parse_line(), checks for new executable declarations in the statement."""
        #This is the same deal as with _rt_parse_types() below.
        if mode == "insert":
            enew, start, end = self.xparser.parse_signature(statement, element, element)
            if enew is not None:
                enew.start, enew.end = lineparser.absolute_charindex(statement, start, end)
                enew.incomplete = True
                element.executables[enew.name.lower()] = enew
                lineparser.additions.append((enew, element))