aml_eval
struct aml_value *aml_eval(struct aml_scope *, struct aml_value *, int, int,
my_ret = aml_eval(scope, my_ret, ret_type, 0, NULL);
my_ret = aml_eval(scope, opargs[0], AML_ARG_INTEGER, 0, NULL);
xres = aml_eval(NULL, node->value, 't', argc, argv);