I wish to combine Gustavo's answer with everyone else's, and raise an important point if you want a certain level of evolutionary "realism".
Which is that "wings", as in, the recognizable complex flight-adapted limbs of most birds, all bats, pterosaurs, and so on, are massively over-engineered for all the purposes suggested here. You could imagine the gargoyles might have "simplified wings" that could be adequate to some of those simpler purposes (like the "targeting" suggestion you accepted as the answer), but I'm betting what you're picturing in your mind is not simplified enough for that, because if it were I'm not sure you'd be calling them "wings".
In other words, none of the purposes described here would result in the evolution of wings, as opposed to simpler appendages. That's a strong claim to make, but I think the pattern in existing nature justifies it - only animals who fly, or whose recent ancestors flew, have wings. Plenty of animals glide, fall in controlled ways, thermoregulate, camouflage, have sexual displays, etc etc etc, and they generally have structures that are adapted for this, but almost never would you call those structures "wings". Because the visual appearance of wings is really hard to separate from their primary function, which is flying.
However all those purposes are completely realistic uses for vestigial wings! "Vestigial" doesn't mean the organ is not used or even useless. It means the organ is no longer used for the purpose it originally evolved to fulfill, which typically means that whatever purpose it serves now, it's massively over-engineered for that purpose and it's pretty visible what its original purpose was. Which is exactly how you describe your gargoyle wings: they're small, useless for flight, but recognizable as wings.
Choosing a current "secondary that became primary" purpose for those wings can inform a lot of what your gargoyle wings are like; how small they are, how many degrees of freedom and muscle control they've retained, have they changed shape or appearance. But making sure those organs did evolve from wings frees you of having to worry about "but why would my targeting organ have this or that extraneous winglike feature".