ast_expression *fold_op (fold_t *, const oper_info *, ast_expression **);
ast_expression *fold_intrin (fold_t *, const char *, ast_expression **);
ast_expression *fold_op (fold_t *, const oper_info *, ast_expression **);
ast_expression *fold_intrin (fold_t *, const char *, ast_expression **);