Auto merge of #63926 - Centril:rollup-6kckn9n, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #63317 (Do not complain about unused code when used in `impl` `Self` type)
 - #63693 (Fully implement or-pattern parsing)
 - #63836 (VxWorks does not provide a way to set the task name except at creation time)
 - #63845 (Removed a confusing FnOnce example)
 - #63855 (Refactor feature gates)
 - #63921 (add link to FileCheck docs)

Failed merges:

r? @ghost

Author: bors

src/libcore/ops/function.rs

@@ -185,14 +185,6 @@ pub trait FnMut<Args> : FnOnce<Args> {
 ///
 /// # Examples
 ///
-/// ## Calling a by-value closure
-///
-/// ```
-/// let x = 5;
-/// let square_x = move || x * x;
-/// assert_eq!(square_x(), 25);
-/// ```
-///
 /// ## Using a `FnOnce` parameter
 ///
 /// ```

src/librustc/middle/dead.rs

@@ -30,10 +30,11 @@ fn should_explore(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
         Some(Node::Item(..)) |
         Some(Node::ImplItem(..)) |
         Some(Node::ForeignItem(..)) |
-        Some(Node::TraitItem(..)) =>
-            true,
-        _ =>
-            false
+        Some(Node::TraitItem(..)) |
+        Some(Node::Variant(..)) |
+        Some(Node::AnonConst(..)) |
+        Some(Node::Pat(..)) => true,
+        _ => false
     }
 }
 
@@ -75,7 +76,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
                 self.check_def_id(res.def_id());
             }
             _ if self.in_pat => {},
-            Res::PrimTy(..) | Res::SelfTy(..) | Res::SelfCtor(..) |
+            Res::PrimTy(..) | Res::SelfCtor(..) |
             Res::Local(..) => {}
             Res::Def(DefKind::Ctor(CtorOf::Variant, ..), ctor_def_id) => {
                 let variant_id = self.tcx.parent(ctor_def_id).unwrap();
@@ -92,6 +93,14 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
                     self.check_def_id(variant_id);
                 }
             }
+            Res::SelfTy(t, i) => {
+                if let Some(t) = t {
+                    self.check_def_id(t);
+                }
+                if let Some(i) = i {
+                    self.check_def_id(i);
+                }
+            }
             Res::ToolMod | Res::NonMacroAttr(..) | Res::Err => {}
             _ => {
                 self.check_def_id(res.def_id());
@@ -271,7 +280,7 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
                 let res = self.tables.qpath_res(path, pat.hir_id);
                 self.handle_field_pattern_match(pat, res, fields);
             }
-            PatKind::Path(ref qpath @ hir::QPath::TypeRelative(..)) => {
+            PatKind::Path(ref qpath) => {
                 let res = self.tables.qpath_res(qpath, pat.hir_id);
                 self.handle_res(res);
             }
@@ -298,6 +307,11 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
         }
         intravisit::walk_ty(self, ty);
     }
+
+    fn visit_anon_const(&mut self, c: &'tcx hir::AnonConst) {
+        self.live_symbols.insert(c.hir_id);
+        intravisit::walk_anon_const(self, c);
+    }
 }
 
 fn has_allow_dead_code_or_lang_attr(

src/libstd/sys/vxworks/thread.rs

@@ -77,7 +77,7 @@ impl Thread {
     }
 
     pub fn set_name(_name: &CStr) {
-        assert!(false, "FIXME: set_name");
+        // VxWorks does not provide a way to set the task name except at creation time
     }
 
     pub fn sleep(dur: Duration) {