Mangle names.

def visit_Identifier(self, node):
        """Mangle names."""
        if not self._is_mangle_candidate(node):
            return
        name = node.value
        symbol = node.scope.resolve(node.value)
        if symbol is None:
            return
        mangled = symbol.scope.mangled.get(name)
        if mangled is not None:
            node.value = mangled