Remove DefRegion, which is not used

src/librustc/middle/astencode.rs

@@ -476,7 +476,6 @@ impl tr for def::Def {
             def::DefUpvar(dcx.tr_id(nid1), index, dcx.tr_id(nid2))
           }
           def::DefStruct(did) => def::DefStruct(did.tr(dcx)),
-          def::DefRegion(nid) => def::DefRegion(dcx.tr_id(nid)),
           def::DefLabel(nid) => def::DefLabel(dcx.tr_id(nid))
         }
     }

src/librustc/middle/def.rs

@@ -50,7 +50,6 @@ pub enum Def {
     /// - If it's an ExprPath referring to some tuple struct, then DefMap maps
     ///   it to a def whose id is the StructDef.ctor_id.
     DefStruct(DefId),
-    DefRegion(ast::NodeId),
     DefLabel(ast::NodeId),
     DefMethod(DefId),
 }
@@ -125,7 +124,7 @@ impl Def {
             DefVariant(..) | DefTy(..) | DefAssociatedTy(..) |
             DefTyParam(..) | DefUse(..) | DefStruct(..) | DefTrait(..) |
             DefMethod(..) | DefConst(..) | DefAssociatedConst(..) |
-            DefPrimTy(..) | DefRegion(..) | DefLabel(..) | DefSelfTy(..) => {
+            DefPrimTy(..) | DefLabel(..) | DefSelfTy(..) => {
                 panic!("attempted .def_id() on invalid {:?}", self)
             }
         }
@@ -143,7 +142,6 @@ impl Def {
 
             DefLocal(id) |
             DefUpvar(id, _, _) |
-            DefRegion(id) |
             DefLabel(id)  |
             DefSelfTy(_, Some((_, id))) => {
                 DefId::xxx_local(id) // TODO, clearly

src/librustc/middle/mem_categorization.rs

@@ -551,7 +551,7 @@ impl<'t, 'a,'tcx> MemCategorizationContext<'t, 'a, 'tcx> {
           }
           def::DefMod(_) | def::DefForeignMod(_) | def::DefUse(_) |
           def::DefTrait(_) | def::DefTy(..) | def::DefPrimTy(_) |
-          def::DefTyParam(..) | def::DefRegion(_) |
+          def::DefTyParam(..) |
           def::DefLabel(_) | def::DefSelfTy(..) |
           def::DefAssociatedTy(..) => {
               Ok(Rc::new(cmt_ {

src/librustc_resolve/build_reduced_graph.rs

@@ -816,7 +816,7 @@ impl<'a, 'b:'a, 'tcx:'b> GraphBuilder<'a, 'b, 'tcx> {
             self.structs.insert(def_id, fields);
           }
           DefLocal(..) | DefPrimTy(..) | DefTyParam(..) |
-          DefUse(..) | DefUpvar(..) | DefRegion(..) |
+          DefUse(..) | DefUpvar(..) |
           DefLabel(..) | DefSelfTy(..) => {
             panic!("didn't expect `{:?}`", def);
           }

src/librustc_trans/save/dump_csv.rs

@@ -264,7 +264,6 @@ impl <'l, 'tcx> DumpCsvVisitor<'l, 'tcx> {
             def::DefFn(..) => Some(recorder::FnRef),
 
             def::DefSelfTy(..) |
-            def::DefRegion(_) |
             def::DefLabel(_) |
             def::DefTyParam(..) |
             def::DefUse(_) |

src/librustc_trans/trans/callee.rs

@@ -215,8 +215,8 @@ fn trans<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, expr: &hir::Expr)
             }
             def::DefMod(..) | def::DefForeignMod(..) | def::DefTrait(..) |
             def::DefTy(..) | def::DefPrimTy(..) | def::DefAssociatedTy(..) |
-            def::DefUse(..) | def::DefRegion(..) | def::DefLabel(..) |
+            def::DefUse(..) | def::DefLabel(..) | def::DefTyParam(..) |
-            def::DefTyParam(..) | def::DefSelfTy(..) => {
+            def::DefSelfTy(..) => {
                 bcx.tcx().sess.span_bug(
                     ref_expr.span,
                     &format!("cannot translate def {:?} \

src/librustc_typeck/check/mod.rs

@@ -4318,7 +4318,6 @@ fn type_scheme_and_predicates_for_def<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
         def::DefMod(..) |
         def::DefForeignMod(..) |
         def::DefUse(..) |
-        def::DefRegion(..) |
         def::DefLabel(..) |
         def::DefSelfTy(..) => {
             fcx.ccx.tcx.sess.span_bug(sp, &format!("expected value, found {:?}", defn));
@@ -4489,7 +4488,6 @@ pub fn instantiate_path<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
         def::DefForeignMod(..) |
         def::DefLocal(..) |
         def::DefUse(..) |
-        def::DefRegion(..) |
         def::DefLabel(..) |
         def::DefUpvar(..) => {
             segment_spaces = vec![None; segments.len()];