Handle spurious failures caused by delayed UB instrumentation

kani-compiler/src/kani_middle/transform/check_uninit/delayed_ub/instrumentation_visitor.rs

@@ -19,7 +19,7 @@ use rustc_middle::ty::TyCtxt;
 use rustc_smir::rustc_internal;
 use stable_mir::mir::{
     visit::{Location, PlaceContext},
-    BasicBlockIdx, MirVisitor, Operand, Place, Statement, Terminator,
+    BasicBlockIdx, MirVisitor, Operand, Place, Rvalue, Statement, Terminator,
 };
 use std::collections::HashSet;
 
@@ -103,6 +103,15 @@ impl<'a, 'tcx> MirVisitor for InstrumentationVisitor<'a, 'tcx> {
         }
     }
 
+    fn visit_rvalue(&mut self, rvalue: &Rvalue, location: Location) {
+        match rvalue {
+            Rvalue::AddressOf(..) | Rvalue::Ref(..) => {
+                // These operations are always legitimate for us.
+            }
+            _ => self.super_rvalue(rvalue, location),
+        }
+    }
+
     fn visit_place(&mut self, place: &Place, ptx: PlaceContext, location: Location) {
         // Match the place by whatever it is pointing to and find an intersection with the targets.
         if self