doc/go1.19: add release note for CL 398058

Change-Id: I483de9a6a2016432df13e030c675d42470db9ed1
Reviewed-on: https://go-review.googlesource.com/c/go/+/409175
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Author: Bryan C. Mills

doc/go1.19.html

@@ -31,9 +31,6 @@ <h2 id="tools">Tools</h2>
   TODO: complete this section, or delete if not needed
 </p>
 <h3 id="go-command">Go command</h3>
-<p>
-  TODO: <a href="https://go.dev/cl/398058">https://go.dev/cl/398058</a>: cmd/go: quote fragments in CGO_ env variables reported by 'go env'
-</p>
 <p>
   TODO: complete this section.
 </p>
@@ -53,6 +50,13 @@ <h3 id="go-command">Go command</h3>
   with <code>-trimpath</code>.
 </p>
 
+<p><!-- CL 398058 -->
+  <code>go</code> <code>env</code> now quotes entries that contain spaces in
+  the <code>CGO_CFLAGS</code>, <code>CGO_CPPFLAGS</code>, <code>CGO_CXXFLAGS</code>, <code>CGO_FFLAGS</code>, <code>CGO_LDFLAGS</code>,
+  and <code>GOGCCFLAGS</code> variables it reports.
+</p>
+
+
 <h4 id="go-unix">New <code>unix</code> build constraint</h4>
 
 <p><!-- CL 389934 -->