Auto merge of rust-lang#104757 - camelid:consolidate-lints, r=GuillaumeGomez,jyn514,Manishearth

Consolidate rustdoc's lint passes into a single pass

This should improve performance and simplify the code.

r? `@GuillaumeGomez`

Author: bors

src/librustdoc/passes/bare_urls.rs

@@ -0,0 +1,33 @@
+//! Runs several rustdoc lints, consolidating them into a single pass for
+//! efficiency and simplicity.
+
+mod bare_urls;
+mod check_code_block_syntax;
+mod html_tags;
+
+use super::Pass;
+use crate::clean::*;
+use crate::core::DocContext;
+use crate::visit::DocVisitor;
+
+pub(crate) const RUN_LINTS: Pass =
+    Pass { name: "run-lints", run: run_lints, description: "runs some of rustdoc's lints" };
+
+struct Linter<'a, 'tcx> {
+    cx: &'a mut DocContext<'tcx>,
+}
+
+pub(crate) fn run_lints(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
+    Linter { cx }.visit_crate(&krate);
+    krate
+}
+
+impl<'a, 'tcx> DocVisitor for Linter<'a, 'tcx> {
+    fn visit_item(&mut self, item: &Item) {
+        bare_urls::visit_item(self.cx, item);
+        check_code_block_syntax::visit_item(self.cx, item);
+        html_tags::visit_item(self.cx, item);
+
+        self.visit_item_recur(item)
+    }
+}