gen_load
gen_load(Q_LINK, gen_loadi(0), 1),
struct arth *gen_load(int, struct arth *, int);
narth: pname '[' arth ']' { $$ = gen_load($1, $3, 1); }
| pname '[' arth ':' NUM ']' { $$ = gen_load($1, $3, $5); }