Why does -inum require stat(2)?

[George Spelvin]

Looking for an inode that fsck complained about, I did a find,
and noticed that it was statting every file name it found.

Hunting through the code, I see that, in tree.c, pred_inum is marked
NeedsStatInfo.  Is there a reason that struct dirent's d_ino field
can't be used instead?  That would drastically reduce the cost of this
predicate.

(This would also benefit pred_samefile.)