Add outlives_constraint to BlameConstraint

Author: jackh726

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -310,11 +310,12 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         borrow_region: RegionVid,
         outlived_region: RegionVid,
     ) -> (ConstraintCategory<'tcx>, bool, Span, Option<RegionName>) {
-        let BlameConstraint { category, from_closure, cause, variance_info: _ } = self
-            .regioncx
-            .best_blame_constraint(borrow_region, NllRegionVariableOrigin::FreeRegion, |r| {
-                self.regioncx.provides_universal_region(r, borrow_region, outlived_region)
-            });
+        let blame_constraint = self.regioncx.best_blame_constraint(
+            borrow_region,
+            NllRegionVariableOrigin::FreeRegion,
+            |r| self.regioncx.provides_universal_region(r, borrow_region, outlived_region),
+        );
+        let BlameConstraint { category, from_closure, cause, .. } = blame_constraint;
 
         let outlived_fr_name = self.give_region_a_name(outlived_region);
 

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -354,7 +354,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     ) {
         debug!("report_region_error(fr={:?}, outlived_fr={:?})", fr, outlived_fr);
 
-        let BlameConstraint { category, cause, variance_info, from_closure: _ } =
+        let BlameConstraint { category, cause, variance_info, .. } =
             self.regioncx.best_blame_constraint(fr, fr_origin, |r| {
                 self.regioncx.provides_universal_region(r, fr, outlived_fr)
             });

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -2073,6 +2073,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     from_closure,
                     cause: ObligationCause::new(span, CRATE_HIR_ID, cause_code),
                     variance_info: constraint.variance_info,
+                    outlives_constraint: *constraint,
                 }
             })
             .collect();
@@ -2328,4 +2329,5 @@ pub struct BlameConstraint<'tcx> {
     pub from_closure: bool,
     pub cause: ObligationCause<'tcx>,
     pub variance_info: ty::VarianceDiagInfo<'tcx>,
+    pub outlives_constraint: OutlivesConstraint<'tcx>,
 }