remove redundant var rebindings

compiler/rustc_middle/src/hir/mod.rs

@@ -164,18 +164,15 @@ pub fn provide(providers: &mut Providers) {
         tcx.hir_crate(()).owners[id.def_id].as_owner().map_or(AttributeMap::EMPTY, |o| &o.attrs)
     };
     providers.def_span = |tcx, def_id| {
-        let def_id = def_id;
         let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
         tcx.hir().opt_span(hir_id).unwrap_or(DUMMY_SP)
     };
     providers.def_ident_span = |tcx, def_id| {
-        let def_id = def_id;
         let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
         tcx.hir().opt_ident_span(hir_id)
     };
-    providers.fn_arg_names = |tcx, id| {
+    providers.fn_arg_names = |tcx, def_id| {
         let hir = tcx.hir();
-        let def_id = id;
         let hir_id = hir.local_def_id_to_hir_id(def_id);
         if let Some(body_id) = hir.maybe_body_owned_by(def_id) {
             tcx.arena.alloc_from_iter(hir.body_param_names(body_id))
@@ -190,7 +187,7 @@ pub fn provide(providers: &mut Providers) {
         {
             idents
         } else {
-            span_bug!(hir.span(hir_id), "fn_arg_names: unexpected item {:?}", id);
+            span_bug!(hir.span(hir_id), "fn_arg_names: unexpected item {:?}", def_id);
         }
     };
     providers.opt_def_kind = |tcx, def_id| tcx.hir().opt_def_kind(def_id);

compiler/rustc_passes/src/layout_test.rs

@@ -27,7 +27,6 @@ pub fn test_layout(tcx: TyCtxt<'_>) {
 }
 
 fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
-    let tcx = tcx;
     let param_env = tcx.param_env(item_def_id);
     let ty = tcx.type_of(item_def_id).instantiate_identity();
     match tcx.layout_of(param_env.and(ty)) {

compiler/rustc_passes/src/liveness.rs

@@ -1105,7 +1105,6 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 }
 
                 // Then do a second pass for inputs
-                let mut succ = succ;
                 for (op, _op_sp) in asm.operands.iter().rev() {
                     match op {
                         hir::InlineAsmOperand::In { expr, .. } => {