try a cold annotation on validate_same_iteration

Author: carljm

src/function/maybe_changed_after.rs

@@ -266,6 +266,7 @@ where
     /// If this is a provisional memo, validate that it was cached in the same iteration of the
     /// same cycle(s) that we are still executing. If so, it is valid for reuse. This avoids
     /// runaway re-execution of the same queries within a fixpoint iteration.
+    #[cold]
     pub(super) fn validate_same_iteration(
         &self,
         db: &C::DbView,