List all cases explicitly in `Doc{Folder,Visitor}`

src/librustdoc/fold.rs

@@ -60,8 +60,26 @@ fn fold_inner_recur(&mut self, kind: ItemKind) -> ItemKind {
                 }
                 Variant::CLike => VariantItem(Variant::CLike),
             },
-            // FIXME: list all cases explicitly
-            x => x,
+            ExternCrateItem { src: _ }
+            | ImportItem(_)
+            | FunctionItem(_)
+            | TypedefItem(_, _)
+            | OpaqueTyItem(_)
+            | StaticItem(_)
+            | ConstantItem(_)
+            | TraitAliasItem(_)
+            | TyMethodItem(_)
+            | MethodItem(_, _)
+            | StructFieldItem(_)
+            | ForeignFunctionItem(_)
+            | ForeignStaticItem(_)
+            | ForeignTypeItem
+            | MacroItem(_)
+            | ProcMacroItem(_)
+            | PrimitiveItem(_)
+            | AssocConstItem(_, _)
+            | AssocTypeItem(_, _)
+            | KeywordItem(_) => kind,
         }
     }
 

src/librustdoc/passes/collect_trait_impls.rs

 use super::Pass;
+use crate::clean::*;
 use crate::core::DocContext;
-use crate::{clean::*, visit::DocVisitor};
+use crate::visit::DocVisitor;
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::DefId;

src/librustdoc/passes/html_tags.rs

@@ -3,9 +3,11 @@
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
 use crate::visit::DocVisitor;
-use core::ops::Range;
+
 use pulldown_cmark::{Event, Parser, Tag};
+
 use std::iter::Peekable;
+use std::ops::Range;
 use std::str::CharIndices;
 
 crate const CHECK_INVALID_HTML_TAGS: Pass = Pass {

src/librustdoc/visit.rs

@@ -23,8 +23,26 @@ fn visit_inner_recur(&mut self, kind: &ItemKind) {
                 Variant::Tuple(fields) => fields.iter().for_each(|x| self.visit_item(x)),
                 Variant::CLike => {}
             },
-            // FIXME: list all cases explicitly
-            _ => return,
+            ExternCrateItem { src: _ }
+            | ImportItem(_)
+            | FunctionItem(_)
+            | TypedefItem(_, _)
+            | OpaqueTyItem(_)
+            | StaticItem(_)
+            | ConstantItem(_)
+            | TraitAliasItem(_)
+            | TyMethodItem(_)
+            | MethodItem(_, _)
+            | StructFieldItem(_)
+            | ForeignFunctionItem(_)
+            | ForeignStaticItem(_)
+            | ForeignTypeItem
+            | MacroItem(_)
+            | ProcMacroItem(_)
+            | PrimitiveItem(_)
+            | AssocConstItem(_, _)
+            | AssocTypeItem(_, _)
+            | KeywordItem(_) => {}
         }
     }