Make sure to walk into nested const blocks in `RegionResolutionVisitor` Fixes https://github.com/rust-lang/rust/issues/135306 I tried auditing the rest of the visitors that called `.visit_body`, and it seems like this is the only one that was missing it. I wonder if we should modify intravisit (specifcially, that `NestedBodyFilter` stuff) to make this less likely to happen, tho... r? oli-obk