doc: release notes for my humble contributions to go1.21

Updates #58645

Change-Id: Ieb4e6062613e26826ba8373cb4c2fd9198d0c692
Reviewed-on: https://go-review.googlesource.com/c/go/+/496116
Reviewed-by: Eli Bendersky <eliben@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Alan Donovan <adonovan@google.com>
TryBot-Bypass: Eli Bendersky <eliben@google.com>

doc/go1.21.html

@@ -60,7 +60,7 @@ <h2 id="ports">Ports</h2>
   <!-- replace CallImport with go:wasmimport directive -->
 </p>
 
-<h3 id="wasip1">WebAssembly</h3>
+<h3 id="wasm">WebAssembly</h3>
 
 <!-- https://go.dev/issue/59149 -->
 <p>
@@ -131,7 +131,7 @@ <h3 id="go-command">Go command</h3>
   <!-- cmd/go: make go test build multiple executables; The go test command now supports using the -c flag with multiple packages. -->
 </p>
 
-<h2 id="runtime">Runtime</h2>
+<h2 id="runtime-changes">Runtime</h2>
 
 <p>
   TODO: complete this section, or delete if not needed
@@ -414,17 +414,18 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <dl id="go/ast"><dt><a href="/pkg/go/ast/">go/ast</a></dt>
   <dd>
-    <p><!-- https://go.dev/issue/28089 -->
-      TODO: <a href="https://go.dev/issue/28089">https://go.dev/issue/28089</a>: add func IsGenerated(*File) bool
+    <p><!-- https://go.dev/issue/28089, CL 487935 -->
+      The new <a href="/pkg/go/ast/#IsGenerated"><code>IsGenerated</code></a> predicate
+      reports whether a file syntax tree contains the
+      <a href="https://go.dev/s/generatedcode">special comment</a>
+      that conventionally indicates that the file was generated by a tool.
     </p>
+  </dd>
 
+  <dd>
     <p><!-- CL 476276 -->
       TODO: <a href="https://go.dev/cl/476276">https://go.dev/cl/476276</a>: go/ast: add File.GoVersion; modified api/next/59033.txt
     </p>
-
-    <p><!-- CL 487935 -->
-      TODO: <a href="https://go.dev/cl/487935">https://go.dev/cl/487935</a>: go/ast: add IsGenerated(*File) predicate; modified api/next/28089.txt
-    </p>
   </dd>
 </dl><!-- go/ast -->
 
@@ -446,8 +447,10 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <dl id="go/token"><dt><a href="/pkg/go/token/">go/token</a></dt>
   <dd>
-    <p><!-- CL 464515 -->
-      TODO: <a href="https://go.dev/cl/464515">https://go.dev/cl/464515</a>: go/token: add (*File).Lines method; modified api/next/57708.txt
+    <p><!-- https://go.dev/issue/57708, CL 464515 -->
+      The new <a href="/pkg/go/token/#File.Lines"><code>File.Lines</code></a> method
+      returns the file's line-number table in the same form as accepted by
+      <code>File.SetLines</code>.
     </p>
   </dd>
 </dl><!-- go/token -->
@@ -554,12 +557,11 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <dl id="math/big"><dt><a href="/pkg/math/big/">math/big</a></dt>
   <dd>
-    <p><!-- https://go.dev/issue/56984 -->
-      TODO: <a href="https://go.dev/issue/56984">https://go.dev/issue/56984</a>: add Int.Float64 conversion (was initially: {ToInt64,ToUint64,Float64})
-    </p>
-
-    <p><!-- CL 453115 -->
-      TODO: <a href="https://go.dev/cl/453115">https://go.dev/cl/453115</a>: math/big: add Int.Float64 conversion; modified api/next/56984.txt
+    <p><!-- https://go.dev/issue/56984, CL 453115 -->
+      The new <a href="/pkg/math/big/#Int.ToFloat64"><code>Int.ToFloat64</code></a>
+      method returns the nearest floating-point value to a
+      multi-precision integer, along with an indication of any
+      rounding that occurred.
     </p>
   </dd>
 </dl><!-- math/big -->