Go through remove_unreachable_allocs

src/borrow_tracker/mod.rs

@@ -236,6 +236,10 @@ impl GlobalStateInner {
             tag
         })
     }
+
+    pub fn remove_unreachable_allocs(&mut self, reachable: &FxHashSet<AllocId>) {
+        self.base_ptr_tags.retain(|id, _| reachable.contains(id));
+    }
 }
 
 /// Which borrow tracking method to use

src/provenance_gc.rs

@@ -185,7 +185,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriInterpCxExt<'mir, 'tcx> {
         this.machine.allocation_spans.borrow_mut().retain(|id, _| allocs.contains(id));
         this.machine.intptrcast.borrow_mut().remove_unreachable_allocs(&allocs);
         if let Some(borrow_tracker) = &this.machine.borrow_tracker {
-            borrow_tracker.borrow_mut().base_ptr_tags.retain(|id, _| allocs.contains(id));
+            borrow_tracker.borrow_mut().remove_unreachable_allocs(&allocs);
         }
     }
 }