Remove redundant dyn-compatibility check.

This check is already handled in
`rustc_trait_selection::traits::fulfill::FulfillProcessor::process_obligation`.

Author: theemathas

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

@@ -771,12 +771,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     Ok(EvaluatedToOkModuloRegions)
                 }
 
-                ty::PredicateKind::DynCompatible(trait_def_id) => {
-                    if self.tcx().is_dyn_compatible(trait_def_id) {
-                        Ok(EvaluatedToOk)
-                    } else {
-                        Ok(EvaluatedToErr)
-                    }
+                ty::PredicateKind::DynCompatible(_) => {
+                    bug!(
+                        "Obligation {obligation:?} should have been handled by fulfillment already."
+                    )
                 }
 
                 ty::PredicateKind::Clause(ty::ClauseKind::Projection(data)) => {