Rollup merge of rust-lang#146484 - notriddle:stringdex-js-opt, r=GuillaumeGomez

rustdoc-search: JavaScript optimization based on Firefox Profiler output

Part of rust-lang#146048

Preview: https://notriddle.com/rustdoc-html-demo-12/stringdex-js-opt/std/index.html

These commits are based on some profiler readings, and should reduce CPU usage for name-based searching.

- The first commit improves warm searches by allocating less garbage when data is already loaded:

  Before: https://profiler.firefox.com/public/wvzd88m8r70p8frvz1z628tv3htwna0b9c0ef10/calltree/?globalTrackOrder=0w2&implementation=js&thread=3&v=11

  After: https://profiler.firefox.com/public/yfe9aq6ep3kacw3zmr7jqn6gv7ckfq86rg89568/calltree/?globalTrackOrder=0w2&implementation=js&thread=3&v=11

- The second commit improves cold searches by delaying load for special type names until type-based search runs

  Before: 5.86s (throttled to "Good 2G" in Dev Tools) <https://doc.rust-lang.org/nightly/std/index.html?search=>

  <img width="2524" height="919" alt="image" src="https://github.com/user-attachments/assets/8dbbbd46-b7ab-4e3c-9e8c-f1e41cfaa968" />

  After: 5.77s (throttled to "Good 2G" in Dev Tools) <https://notriddle.com/rustdoc-html-demo-12/stringdex-js-opt/std/index.html?search=>

  <img width="2524" height="912" alt="image" src="https://github.com/user-attachments/assets/6976a584-24f4-4d47-8118-7a81b22d411e" />

  For comparison's sake, the same test takes 12.17s on stable <https://doc.rust-lang.org/1.89.0/std/index.html?search=>

    <img width="2525" height="916" alt="image" src="https://github.com/user-attachments/assets/eb6df2e8-6632-4bef-a6d0-5179c6288fd0" />

Author: Zalathar

src/librustdoc/html/static/js/rustdoc.d.ts

@@ -348,7 +348,7 @@ declare namespace rustdoc {
         returned: rustdoc.QueryElement[],
         is_alias: boolean,
         alias?: string,
-        original?: rustdoc.Rlow,
+        item: rustdoc.Row,
     }
 
     /**
@@ -533,4 +533,27 @@ declare namespace rustdoc {
      * Generated by `render_call_locations` in `render/mod.rs`.
      */
     type ScrapedLoc = [[number, number], string, string]
+
+    /**
+     * Each of these identifiers are used specially by
+     * type-driven search. Most of them are lang items
+     * in the compiler.
+     */
+    type TypeNameIds = {
+        "typeNameIdOfOutput": number,
+        "typeNameIdOfFnPtr": number,
+        "typeNameIdOfFn": number,
+        "typeNameIdOfFnMut": number,
+        "typeNameIdOfFnOnce": number,
+        "typeNameIdOfArray": number,
+        "typeNameIdOfSlice": number,
+        "typeNameIdOfArrayOrSlice": number,
+        "typeNameIdOfTuple": number,
+        "typeNameIdOfUnit": number,
+        "typeNameIdOfTupleOrUnit": number,
+        "typeNameIdOfReference": number,
+        "typeNameIdOfPointer": number,
+        "typeNameIdOfHof": number,
+        "typeNameIdOfNever": number,
+    };
 }