Fix tests

This is just undoing changes from #41991 because we are not running markdown rendering twice.

Author: nrc

src/libstd/io/mod.rs

@@ -212,7 +212,7 @@
 //! # }
 //! ```
 //!
-//! [functions-list]: #functions-2
+//! [functions-list]: #functions-1
 //!
 //! ## io::Result
 //!

src/test/rustdoc/issue-29449.rs

@@ -18,12 +18,12 @@ impl Foo {
     /// # Panics
     pub fn bar() {}
 
-    // @has - '//*[@id="examples-2"]//a' 'Examples'
+    // @has - '//*[@id="examples-1"]//a' 'Examples'
     /// # Examples
     pub fn bar_1() {}
 
-    // @has - '//*[@id="examples-4"]//a' 'Examples'
-    // @has - '//*[@id="panics-2"]//a' 'Panics'
+    // @has - '//*[@id="examples-2"]//a' 'Examples'
+    // @has - '//*[@id="panics-1"]//a' 'Panics'
     /// # Examples
     /// # Panics
     pub fn bar_2() {}