Remove ToUniverseInfo impl for CanonicalQueryInput<CustomTypeOp>.

It's unused.

Author: nnethercote

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -3,7 +3,6 @@ use std::rc::Rc;
 
 use rustc_errors::Diag;
 use rustc_hir::def_id::LocalDefId;
-use rustc_infer::infer::canonical::CanonicalQueryInput;
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
 use rustc_infer::infer::{
     InferCtxt, RegionResolutionError, RegionVariableOrigin, SubregionOrigin, TyCtxtInferExt as _,
@@ -21,7 +20,6 @@ use rustc_span::Span;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::infer::nice_region_error::NiceRegionError;
 use rustc_trait_selection::traits::ObligationCtxt;
-use rustc_trait_selection::traits::query::type_op;
 use rustc_traits::{type_op_ascribe_user_type_with_span, type_op_prove_predicate_with_cause};
 use tracing::{debug, instrument};
 
@@ -117,13 +115,6 @@ impl<'tcx> ToUniverseInfo<'tcx> for CanonicalTypeOpAscribeUserTypeGoal<'tcx> {
     }
 }
 
-impl<'tcx, F> ToUniverseInfo<'tcx> for CanonicalQueryInput<'tcx, type_op::custom::CustomTypeOp<F>> {
-    fn to_universe_info(self, _base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
-        // We can't rerun custom type ops.
-        UniverseInfo::other()
-    }
-}
-
 impl<'tcx> ToUniverseInfo<'tcx> for ! {
     fn to_universe_info(self, _base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
         self