Rollup merge of #112163 - bvanjoi:fix-105231-2, r=compiler-errors

fix: inline `predicate_may_hold_fatal` and remove expect call in it

- Fixes #105231
- Discussion: https://github.com/rust-lang/rust/pull/111985#discussion_r1208888821

r? ``@compiler-errors``

compiler/rustc_trait_selection/src/traits/coherence.rs

@@ -292,7 +292,12 @@ fn impl_intersection_has_impossible_obligation<'cx, 'tcx>(
             Obligation::new(infcx.tcx, ObligationCause::dummy(), param_env, predicate)
         })
         .chain(obligations)
-        .find(|o| !selcx.predicate_may_hold_fatal(o));
+        .find(|o| {
+            selcx.evaluate_root_obligation(o).map_or(
+                false, // Overflow has occurred, and treat the obligation as possibly holding.
+                |result| !result.may_apply(),
+            )
+        });
 
     if let Some(failing_obligation) = opt_failing_obligation {
         debug!("overlap: obligation unsatisfiable {:?}", failing_obligation);

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -518,19 +518,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     // The result is "true" if the obligation *may* hold and "false" if
     // we can be sure it does not.
 
-    /// Evaluates whether the obligation `obligation` can be satisfied (by any means).
-    pub fn predicate_may_hold_fatal(&mut self, obligation: &PredicateObligation<'tcx>) -> bool {
-        debug!(?obligation, "predicate_may_hold_fatal");
-
-        // This fatal query is a stopgap that should only be used in standard mode,
-        // where we do not expect overflow to be propagated.
-        assert!(self.query_mode == TraitQueryMode::Standard);
-
-        self.evaluate_root_obligation(obligation)
-            .expect("Overflow should be caught earlier in standard query mode")
-            .may_apply()
-    }
-
     /// Evaluates whether the obligation `obligation` can be satisfied
     /// and returns an `EvaluationResult`. This is meant for the
     /// *initial* call.