Remove usage of DUMMY_HIR_ID in calls to ObligationClause::misc

Use `ObligationClause::dummy()` when appropriate or replace
`hir::DUMMY_HIR_ID` by `hir::CRATE_HIR_ID`, as used in
`ObligationClause::dummy()`.

Author: marmeladema

src/librustc_trait_selection/traits/auto_trait.rs

@@ -187,13 +187,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
             // to store all of the necessary region/lifetime bounds in the InferContext, as well as
             // an additional sanity check.
             let mut fulfill = FulfillmentContext::new();
-            fulfill.register_bound(
-                &infcx,
-                full_env,
-                ty,
-                trait_did,
-                ObligationCause::misc(DUMMY_SP, hir::DUMMY_HIR_ID),
-            );
+            fulfill.register_bound(&infcx, full_env, ty, trait_did, ObligationCause::dummy());
             fulfill.select_all_or_error(&infcx).unwrap_or_else(|e| {
                 panic!("Unable to fulfill trait {:?} for '{:?}': {:?}", trait_did, ty, e)
             });
@@ -292,7 +286,7 @@ impl AutoTraitFinder<'tcx> {
             user_env.caller_bounds.iter().cloned().collect();
 
         let mut new_env = param_env;
-        let dummy_cause = ObligationCause::misc(DUMMY_SP, hir::DUMMY_HIR_ID);
+        let dummy_cause = ObligationCause::dummy();
 
         while let Some(pred) = predicates.pop_front() {
             infcx.clear_caches();
@@ -615,7 +609,7 @@ impl AutoTraitFinder<'tcx> {
         select: &mut SelectionContext<'_, 'tcx>,
         only_projections: bool,
     ) -> bool {
-        let dummy_cause = ObligationCause::misc(DUMMY_SP, hir::DUMMY_HIR_ID);
+        let dummy_cause = ObligationCause::dummy();
 
         for (obligation, mut predicate) in nested.map(|o| (o.clone(), o.predicate)) {
             let is_new_pred = fresh_preds.insert(self.clean_pred(select.infcx(), predicate));

src/librustc_trait_selection/traits/mod.rs

@@ -31,7 +31,7 @@ use rustc_middle::middle::region;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
 use rustc_middle::ty::{self, GenericParamDefKind, ToPredicate, Ty, TyCtxt, WithConstness};
-use rustc_span::{Span, DUMMY_SP};
+use rustc_span::Span;
 
 use std::fmt::Debug;
 
@@ -136,7 +136,7 @@ pub fn type_known_to_meet_bound_modulo_regions<'a, 'tcx>(
     let trait_ref = ty::TraitRef { def_id, substs: infcx.tcx.mk_substs_trait(ty, &[]) };
     let obligation = Obligation {
         param_env,
-        cause: ObligationCause::misc(span, hir::DUMMY_HIR_ID),
+        cause: ObligationCause::misc(span, hir::CRATE_HIR_ID),
         recursion_depth: 0,
         predicate: trait_ref.without_const().to_predicate(),
     };
@@ -163,7 +163,7 @@ pub fn type_known_to_meet_bound_modulo_regions<'a, 'tcx>(
         // We can use a dummy node-id here because we won't pay any mind
         // to region obligations that arise (there shouldn't really be any
         // anyhow).
-        let cause = ObligationCause::misc(span, hir::DUMMY_HIR_ID);
+        let cause = ObligationCause::misc(span, hir::CRATE_HIR_ID);
 
         fulfill_cx.register_bound(infcx, param_env, ty, def_id, cause);
 

src/librustc_traits/normalize_projection_ty.rs

@@ -1,10 +1,8 @@
-use rustc_hir as hir;
 use rustc_infer::infer::canonical::{Canonical, QueryResponse};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::TraitEngineExt as _;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{ParamEnvAnd, TyCtxt};
-use rustc_span::DUMMY_SP;
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
 use rustc_trait_selection::traits::query::{
     normalize::NormalizationResult, CanonicalProjectionGoal, NoSolution,
@@ -27,7 +25,7 @@ fn normalize_projection_ty<'tcx>(
         &goal,
         |infcx, fulfill_cx, ParamEnvAnd { param_env, value: goal }| {
             let selcx = &mut SelectionContext::new(infcx);
-            let cause = ObligationCause::misc(DUMMY_SP, hir::DUMMY_HIR_ID);
+            let cause = ObligationCause::dummy();
             let mut obligations = vec![];
             let answer = traits::normalize_projection_type(
                 selcx,