rustdoc-search: delay loading type name IDs until type search

This avoids blocking on these lookups, so name-based searches
return results more quickly.

Author: notriddle

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,
+    };
 }