doc: update gccgo docs
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/10401046
diff --git a/doc/gccgo_contribute.html b/doc/gccgo_contribute.html
index b2a0b65..ad2ce46a 100644
--- a/doc/gccgo_contribute.html
+++ b/doc/gccgo_contribute.html
@@ -10,6 +10,10 @@
see <a href="/doc/contribute.html">Contributing to the Go project</a>. For
information on building gccgo for yourself,
see <a href="/doc/gccgo_install.html">Setting up and using gccgo</a>.
+For more of the gritty details on the process of doing development
+with the gccgo frontend,
+see <a href="https://code.google.com/p/gofrontend/source/browse/HACKING">the
+file HACKING</a> in the gofrontend repository.
</p>
<h2>Legal Prerequisites</h2>
