Rollup merge of #76318 - scottmcm:one-control-flow, r=ecstatic-morse

Rollup merge of #76318 - scottmcm:one-control-flow, r=ecstatic-morse

Use ops::ControlFlow in rustc_data_structures::graph::iterate

Since I only know about this because you mentioned it,
r? @ecstatic-morse

If we're not supposed to use new `core` things in compiler for a while then feel free to close, but it felt reasonable to merge the two types since they're the same, and it might be convenient for people to use `?` in their traversal code.

(This doesn't do the type parameter swap; NoraCodes has signed up to do that one.)