cleanup: don't use node_to_hir_id where unneeded

src/librustc/cfg/construct.rs

@@ -99,7 +99,6 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
     }
 
     fn stmt(&mut self, stmt: &hir::Stmt, pred: CFGIndex) -> CFGIndex {
-        let hir_id = self.tcx.hir().node_to_hir_id(stmt.id);
         let exit = match stmt.node {
             hir::StmtKind::Local(ref local) => {
                 let init_exit = self.opt_expr(&local.init, pred);
@@ -113,7 +112,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                 self.expr(&expr, pred)
             }
         };
-        self.add_ast_node(hir_id.local_id, &[exit])
+        self.add_ast_node(stmt.hir_id.local_id, &[exit])
     }
 
     fn pat(&mut self, pat: &hir::Pat, pred: CFGIndex) -> CFGIndex {

src/librustc/infer/error_reporting/nice_region_error/find_anon_type.rs

@@ -114,7 +114,7 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for FindNestedTypeVisitor<'a, 'gcx, 'tcx> {
 
             hir::TyKind::Rptr(ref lifetime, _) => {
                 // the lifetime of the TyRptr
-                let hir_id = self.tcx.hir().node_to_hir_id(lifetime.id);
+                let hir_id = lifetime.hir_id;
                 match (self.tcx.named_region(hir_id), self.bound_region) {
                     // Find the index of the anonymous region that was part of the
                     // error. We will then search the function parameters for a bound
@@ -221,8 +221,7 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for TyPathVisitor<'a, 'gcx, 'tcx> {
     }
 
     fn visit_lifetime(&mut self, lifetime: &hir::Lifetime) {
-        let hir_id = self.tcx.hir().node_to_hir_id(lifetime.id);
-        match (self.tcx.named_region(hir_id), self.bound_region) {
+        match (self.tcx.named_region(lifetime.hir_id), self.bound_region) {
             // the lifetime of the TyPath!
             (Some(rl::Region::LateBoundAnon(debruijn_index, anon_index)), ty::BrAnon(br_index)) => {
                 if debruijn_index == self.current_index && anon_index == br_index {

src/librustc/middle/region.rs

@@ -840,7 +840,7 @@ fn resolve_pat<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, pat: &
 }
 
 fn resolve_stmt<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'a, 'tcx>, stmt: &'tcx hir::Stmt) {
-    let stmt_id = visitor.tcx.hir().node_to_hir_id(stmt.id).local_id;
+    let stmt_id = stmt.hir_id.local_id;
     debug!("resolve_stmt(stmt.id={:?})", stmt_id);
 
     // Every statement will clean up the temporaries created during

src/librustc_mir/hair/cx/block.rs

@@ -46,7 +46,7 @@ fn mirror_stmts<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                                 -> Vec<StmtRef<'tcx>> {
     let mut result = vec![];
     for (index, stmt) in stmts.iter().enumerate() {
-        let hir_id = cx.tcx.hir().node_to_hir_id(stmt.id);
+        let hir_id = stmt.hir_id;
         let opt_dxn_ext = cx.region_scope_tree.opt_destruction_scope(hir_id.local_id);
         let stmt_span = StatementSpan(cx.tcx.hir().span(stmt.id));
         match stmt.node {

src/librustc_typeck/astconv.rs

@@ -114,8 +114,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
             tcx.hir().name(tcx.hir().as_local_node_id(def_id).unwrap()).as_interned_str()
         };
 
-        let hir_id = tcx.hir().node_to_hir_id(lifetime.id);
-        let r = match tcx.named_region(hir_id) {
+        let r = match tcx.named_region(lifetime.hir_id) {
             Some(rl::Region::Static) => {
                 tcx.types.re_static
             }
@@ -1145,8 +1144,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
             self.ast_region_to_region(lifetime, None)
         } else {
             self.compute_object_lifetime_bound(span, existential_predicates).unwrap_or_else(|| {
-                let hir_id = tcx.hir().node_to_hir_id(lifetime.id);
-                if tcx.named_region(hir_id).is_some() {
+                if tcx.named_region(lifetime.hir_id).is_some() {
                     self.ast_region_to_region(lifetime, None)
                 } else {
                     self.re_infer(span, None).unwrap_or_else(|| {

src/librustc_typeck/collect.rs

@@ -814,8 +814,7 @@ fn has_late_bound_regions<'a, 'tcx>(
                 return;
             }
 
-            let hir_id = self.tcx.hir().node_to_hir_id(lt.id);
-            match self.tcx.named_region(hir_id) {
+            match self.tcx.named_region(lt.hir_id) {
                 Some(rl::Region::Static) | Some(rl::Region::EarlyBound(..)) => {}
                 Some(rl::Region::LateBound(debruijn, _, _))
                 | Some(rl::Region::LateBoundAnon(debruijn, _)) if debruijn < self.outer_index => {}
@@ -841,8 +840,7 @@ fn has_late_bound_regions<'a, 'tcx>(
         };
         for param in &generics.params {
             if let GenericParamKind::Lifetime { .. } = param.kind {
-                let hir_id = tcx.hir().node_to_hir_id(param.id);
-                if tcx.is_late_bound(hir_id) {
+                if tcx.is_late_bound(param.hir_id) {
                     return Some(param.span);
                 }
             }

src/librustdoc/clean/mod.rs

@@ -1210,8 +1210,7 @@ impl Lifetime {
 impl Clean<Lifetime> for hir::Lifetime {
     fn clean(&self, cx: &DocContext) -> Lifetime {
         if self.id != ast::DUMMY_NODE_ID {
-            let hir_id = cx.tcx.hir().node_to_hir_id(self.id);
-            let def = cx.tcx.named_region(hir_id);
+            let def = cx.tcx.named_region(self.hir_id);
             match def {
                 Some(rl::Region::EarlyBound(_, node_id, _)) |
                 Some(rl::Region::LateBound(_, node_id, _)) |