[llvm] [TableGen] Use std::move instead of swap. NFC. (PR #81606)

[Sergei Barannikov via llvm-commits]

https://github.com/s-barannikov approved this pull request.

FWIW There is also `llvm::set_intersect` that could modify `ContainingSet` in-place. It does not accept a '<' comparator though, so migh not be suitable.


https://github.com/llvm/llvm-project/pull/81606