cgen: mark &Array.sorted_with_compare as used

[felipensp]

Fix #21907

[spytheman]

It should not be whitelisted imho.

In the lsv project, the call to .sort_with_compare(), is not implicit, and done on the whim of the cgen stage (and thus unpredictable from the markused stage).

The call is present in the user program, and reachable through main -> lsv -> sort:

sorted << groups[key].sorted_with_compare(cmp)

(that is from lsv/lsv/sort.v:68)

v.markused should be improved instead, to handle that case/ast node, and mark it as used without a special case in the whitelist.

[spytheman]

I have a patch, that does it. I'll make a PR after the local tests pass:

[spytheman]

I've pushed #21914 .

[felipensp]

It should not be whitelisted imho.

In the lsv project, the call to .sort_with_compare(), is not implicit, and done on the whim of the cgen stage (and thus unpredictable from the markused stage).

The call is present in the user program, and reachable through main -> lsv -> sort:

sorted << groups[key].sorted_with_compare(cmp)

(that is from lsv/lsv/sort.v:68)

v.markused should be improved instead, to handle that case/ast node, and mark it as used without a special case in the whitelist.

Yeah, good catch. I recently got a weird case where v_fixed_index got removed with -skip-unused too.