Auto merge of #109917 - compiler-errors:remove-relation-methods, r=oli-obk

Remove `intercrate` and `mark_ambiguous` from `TypeRelation`

Fixes #109863

Pulls this logic into `super_combine_tys`, which has access to `InferCtxt` and takes a `ObligationEmittingRelation` -- both of which simplify the logic here.

r? `@oli-obk` `@aliemjay`

compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs

@@ -21,10 +21,6 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> {
         self.infcx.tcx
     }
 
-    fn intercrate(&self) -> bool {
-        false
-    }
-
     fn param_env(&self) -> ty::ParamEnv<'tcx> {
         self.param_env
     }
@@ -33,10 +29,6 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> {
         true
     }
 
-    fn mark_ambiguous(&mut self) {
-        bug!()
-    }
-
     fn relate_with_variance<T: Relate<'tcx>>(
         &mut self,
         _: ty::Variance,