unary_minus(const_expr) will compute const_expr on fix_fields

create table t1 (a int);

insert into t1 select seq from seq_1_to_10;

create table t2 (a int, b int);

insert into t2 select seq,seq from seq_1_to_10000;

explain select -(select max(a) from t2) from t1;

analyze format=json select -(select max(a) from t2) from t1;

{

  "query_optimization": {

    "r_total_time_ms": 7413.537268

  },

  "query_block": {

    "select_id": 1,

    "cost": 0.0124848,

    "r_loops": 1,

    "r_total_time_ms": 0.095447472,

...