Remove unnecessary clone when redundantly adding resource to tracker

[cwfitzgerald]

Related #7856

This removes unnecessary clones of resources which are already owned by the tracker.

Squash.

Edit: ayy funny number

[Wumpf]

nice! Would be great though to see benchmarks justifying this. Yes, this looks faster and should help addressing one of our key hotspots, but I think we should hold ourselves to a high standard and justify this kind of added complexity/indirection with data.
("Request changes" bc of that.)

[Wumpf]

name isn't great, suggests a generality that isn't intended here. Maybe InsertableResource would be better already?

[cwfitzgerald]

I had some profiles a while ago that pointed directly there, but they were in rend3 and vtune on an old machine so don't have them anymore. I'm not entirely sure what whole-stack tests are out there, but I'll poke around.

[Wumpf]

I'd think some of our existing benchmarks in the repo should hit this quite a bit as well

[cwfitzgerald]

@Wumpf I have bad news.... The thing this PR is solving for doesn't happen.... At all. Yes there is a "redundant" clone when inserting a new resource, but that only happens (in hot code) inside a

let currently_owned = unsafe { self.metadata.contains_unchecked(index) };

if !currently_owned {
    clone happens in here
}

so...

uhh

Closing this...