Rollup merge of rust-lang#110371 - notriddle:notriddle/search-corrections, r=GuillaumeGomez

rustdoc: restructure type search engine to pick-and-use IDs

Fixes rust-lang#110029

Preview: https://notriddle.com/rustdoc-demo-html-3/search-corrections/std/index.html?search=-%3E%20streaming

![image](https://user-images.githubusercontent.com/1593513/233494900-ae77d5b4-e395-41f8-bbac-53ee55bb4a76.png)

This change makes it so, instead of mixing string distance with type unification, function signature search works by mapping names to IDs at the start, reporting to the user any cases where it had to make corrections, and then matches with IDs when going through the items.

This only changes function searches. Name searches are left alone, and corrections are only done when there's a single item in the search query.

Author: Manishearth

src/librustdoc/html/static/css/rustdoc.css

@@ -1259,6 +1259,10 @@ a.tooltip:hover::after {
 	background-color: var(--search-error-code-background-color);
 }
 
+.search-corrections {
+	font-weight: normal;
+}
+
 #src-sidebar-toggle {
 	position: sticky;
 	top: 0;

src/librustdoc/html/static/js/externs.js

@@ -9,6 +9,7 @@ function initSearch(searchIndex){}
 /**
  * @typedef {{
  *     name: string,
+ *     id: integer,
  *     fullPath: Array<string>,
  *     pathWithoutLast: Array<string>,
  *     pathLast: string,
@@ -36,6 +37,8 @@ let ParserState;
  *     args: Array<QueryElement>,
  *     returned: Array<QueryElement>,
  *     foundElems: number,
+ *     literalSearch: boolean,
+ *     corrections: Array<{from: string, to: integer}>,
  * }}
  */
 let ParsedQuery;
@@ -139,7 +142,7 @@ let FunctionSearchType;
 
 /**
  * @typedef {{
- *     name: (null|string),
+ *     id: (null|number),
  *     ty: (null|number),
  *     generics: Array<FunctionType>,
  * }}