doc/go1.20: mention -lresolv requirement for c-archive on macOS

For golang/go#58159

Change-Id: I4099bba337acdb82e61cddcf099aa4c1c464d387
Reviewed-on: https://go-review.googlesource.com/c/website/+/470856
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>

_content/doc/go1.20.html

@@ -233,6 +233,14 @@ Do not send CLs removing the interior tags from such phrases.
   On other systems, builds with cgo disabled will use a pure Go version of these packages.
 </p>
 
+<p>
+  A consequence is that, on macOS, if Go code that uses
+  the <code>net</code> package is built
+  with <code>-buildmode=c-archive</code>, linking the resulting
+  archive into a C program requires passing <code>-lresolv</code> when
+  linking the C code.
+</p>
+
 <p>
   On macOS, the race detector has been rewritten not to use cgo:
   race-detector-enabled programs can be built and run without Xcode.