Made 2-of-same-item apply to OVERSIZE items as well.

Nothing else was changed, so OVERSIZE still ignores every check other
than it being wearable in the first place and not mixing normal and
power armor. In some cases that still leads to silliness, but the
tripling-up check seemed like an uncontroversial thing to pull.

It's oversized, sure, but it's not THAT oversized.
Merge pull request #7920 from rluddy/it-is-not-that-oversized

Made 2-of-same-item apply to OVERSIZE items as well.