fix clippy::{needless_bool, manual_unwrap_or}

compiler/rustc_mir/src/transform/early_otherwise_branch.rs

@@ -216,9 +216,10 @@ impl<'a, 'tcx> Helper<'a, 'tcx> {
         let discr = self.find_switch_discriminant_info(bb, switch)?;
 
         // go through each target, finding a discriminant read, and a switch
-        let results = discr.targets_with_values.iter().map(|(value, target)| {
-            self.find_discriminant_switch_pairing(&discr, *target, *value)
-        });
+        let results = discr
+            .targets_with_values
+            .iter()
+            .map(|(value, target)| self.find_discriminant_switch_pairing(&discr, *target, *value));
 
         // if the optimization did not apply for one of the targets, then abort
         if results.clone().any(|x| x.is_none()) || results.len() == 0 {

compiler/rustc_session/src/session.rs

@@ -1109,10 +1109,7 @@ impl Session {
     }
 
     pub fn link_dead_code(&self) -> bool {
-        match self.opts.cg.link_dead_code {
-            Some(explicitly_set) => explicitly_set,
-            None => false,
-        }
+        self.opts.cg.link_dead_code.unwrap_or(false)
     }
 
     pub fn mark_attr_known(&self, attr: &Attribute) {

compiler/rustc_typeck/src/check/upvar.rs

@@ -297,9 +297,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     closure_captures.insert(*var_hir_id, upvar_id);
 
-                    let new_capture_kind = if let Some(capture_kind) =
-                        upvar_capture_map.get(&upvar_id)
-                    {
+                    let new_capture_kind =
+                        if let Some(capture_kind) = upvar_capture_map.get(&upvar_id) {
                             // upvar_capture_map only stores the UpvarCapture (CaptureKind),
                             // so we create a fake capture info with no expression.
                             let fake_capture_info =

compiler/rustc_typeck/src/collect.rs

@@ -2141,13 +2141,8 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
             // * It must be an associated type for this trait (*not* a
             //   supertrait).
             if let ty::Projection(projection) = ty.kind() {
-                if projection.substs == trait_identity_substs
+                projection.substs == trait_identity_substs
                     && tcx.associated_item(projection.item_def_id).container.id() == def_id
-                {
-                    true
-                } else {
-                    false
-                }
             } else {
                 false
             }

src/bootstrap/sanity.rs

@@ -159,11 +159,7 @@ pub fn check(build: &mut Build) {
             panic!("the iOS target is only supported on macOS");
         }
 
-        build
-            .config
-            .target_config
-            .entry(*target)
-            .or_insert(Target::from_triple(&target.triple));
+        build.config.target_config.entry(*target).or_insert(Target::from_triple(&target.triple));
 
         if target.contains("-none-") || target.contains("nvptx") {
             if build.no_std(*target) == Some(false) {