'Restore all aliases and delete unused variables.'

def pop_scope(self, aliases, frame):

    for (name, alias) in aliases.iteritems():
        self.writeline(('l_%s    =    %s' % (name, alias)))
    to_delete = set()
    for name in frame.identifiers.declared_locally:
        if (name not in aliases):
            to_delete.add(('l_' + name))
    if to_delete:
        self.writeline(('    =    '.join(to_delete) + '    =    missing'))
