Re-enable "jump to def" feature on rustc docs

Author: GuillaumeGomez

compiler/rustc_interface/src/passes.rs

@@ -827,7 +827,7 @@ fn run_required_analyses(tcx: TyCtxt<'_>) {
     if tcx.sess.opts.unstable_opts.input_stats {
         rustc_passes::input_stats::print_hir_stats(tcx);
     }
-    #[cfg(debug_assertions)]
+    #[cfg(all(not(doc), debug_assertions))]
     rustc_passes::hir_id_validator::check_crate(tcx);
     let sess = tcx.sess;
     sess.time("misc_checking_1", || {

src/bootstrap/src/core/build_steps/doc.rs

@@ -845,6 +845,9 @@ impl Step for Rustc {
         cargo.rustdocflag("--extern-html-root-url");
         cargo.rustdocflag("ena=https://docs.rs/ena/latest/");
 
+        // Enabling the "jump to def" feature on rustc's source code pages.
+        cargo.rustdocflag("--generate-link-to-definition");
+
         let mut to_open = None;
 
         let out_dir = builder.stage_out(compiler, Mode::Rustc).join(target).join("doc");