Make PlaceRef lifetimes of borrow_conflict_place be both 'tcx

Author: spastorino

src/librustc_mir/borrow_check/mod.rs

@@ -86,6 +86,8 @@ crate struct Upvar {
     mutability: Mutability,
 }
 
+const DEREF_PROJECTION: &[PlaceElem<'_>; 1] = &[ProjectionElem::Deref];
+
 pub fn provide(providers: &mut Providers<'_>) {
     *providers = Providers { mir_borrowck, ..*providers };
 }
@@ -1413,7 +1415,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     ) {
         debug!("check_for_invalidation_at_exit({:?})", borrow);
         let place = &borrow.borrowed_place;
-        let deref = [ProjectionElem::Deref];
         let mut root_place = PlaceRef { local: place.local, projection: &[] };
 
         // FIXME(nll-rfc#40): do more precise destructor tracking here. For now
@@ -1427,7 +1428,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 // Thread-locals might be dropped after the function exits
                 // We have to dereference the outer reference because
                 // borrows don't conflict behind shared references.
-                root_place.projection = &deref;
+                root_place.projection = DEREF_PROJECTION;
                 (true, true)
             } else {
                 (false, self.locals_are_invalidated_at_exit)

src/librustc_mir/borrow_check/places_conflict.rs

@@ -48,7 +48,7 @@ pub(super) fn borrow_conflicts_with_place<'tcx>(
     body: &Body<'tcx>,
     borrow_place: &Place<'tcx>,
     borrow_kind: BorrowKind,
-    access_place: PlaceRef<'_, 'tcx>,
+    access_place: PlaceRef<'tcx, 'tcx>,
     access: AccessDepth,
     bias: PlaceConflictBias,
 ) -> bool {
@@ -73,7 +73,7 @@ fn place_components_conflict<'tcx>(
     body: &Body<'tcx>,
     borrow_place: &Place<'tcx>,
     borrow_kind: BorrowKind,
-    access_place: PlaceRef<'_, 'tcx>,
+    access_place: PlaceRef<'tcx, 'tcx>,
     access: AccessDepth,
     bias: PlaceConflictBias,
 ) -> bool {