Auto merge of #88533 - oli-obk:tait_🧊, r=spastorino

Concrete regions can show up in mir borrowck if the originated from there

We used to not encounter them here, because we took regions from typeck's opaque type resolution by renumbering them. We don't do that anymore. Instead mir borrock does all the logic, and it can handle concrete regions just fine, as long as it created them itself.

fixes #83190 which was introduced by #87287

r? `@spastorino`

1 files changed, 1 insertions, 9 deletions

diff --git a/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs b/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
index e9ab62e1664..12fceeff088 100644
--- a/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
+++ b/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
@@ -82,15 +82,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                             .find(|ur_vid| self.eval_equal(vid, **ur_vid))
                             .and_then(|ur_vid| self.definitions[*ur_vid].external_name)
                             .unwrap_or(infcx.tcx.lifetimes.re_root_empty),
-                        ty::ReLateBound(..) => region,
-                        ty::ReStatic => region,
-                        _ => {
-                            infcx.tcx.sess.delay_span_bug(
-                                span,
-                                &format!("unexpected concrete region in borrowck: {:?}", region),
-                            );
-                            region
-                        }
+                        _ => region,
                     });
 
                 debug!(?universal_concrete_type, ?universal_substs);