gccgo_install.html: Description of the port to RTEMS added.

R=iant, r
CC=gofrontend-dev, golang-dev, joel.sherrill
https://golang.org/cl/1846047

doc/gccgo_install.html

@@ -395,3 +395,15 @@ grep '#GO' foo.s | grep -v INVALID | grep -v unknowndefine | grep -v undef > foo
 This procedure is full of unstated caveats and restrictions and we make no
 guarantee that it will not change in the future. It is more useful as a
 starting point for real Go code than as a regular procedure.
+
+<h2 id="RTEMS Port">RTEMS Port</h2>
+<p>
+The <code>gccgo</code> compiler has been ported to <a href="http://www.rtems.com/"
+<code>RTEMS</code></a>. <code>RTEMS</code> is a real-time executive
+that provides a high performance environment for embedded applications
+on a range of processors and embedded hardware. The current <code>gccgo</code>
+port is for x86. The goal is to extend the port to most of the
+<a href="http://www.rtems.org/wiki/index.php/SupportedCPUs">
+architectures supported by <code>RTEMS</code></a>. For more information on the port,
+as well as instructions on how to install it, please see this
+<a href="http://www.rtems.com/wiki/index.php/GCCGoRTEMS"><code>RTEMS</code> Wiki page</a>.