Fixes #3206.
R=golang-dev, gri, bradfitz
CC=golang-dev
https://golang.org/cl/
5769046
<p>
Choices for <code>$GOOS</code> are
-<code>darwin</code> (Mac OS X 10.5 and above), <code>freebsd</code>,
+<code>darwin</code> (Mac OS X 10.6 and above), <code>freebsd</code>,
<code>linux</code>, <code>netbsd</code>, <code>openbsd</code>,
<code>plan9</code>, and <code>windows</code>.
Choices for <code>$GOARCH</code> are
<p>
Official binary distributions are available
-for the FreeBSD, Linux, Mac OS X, and Windows operating systems
+for the FreeBSD, Linux, Mac OS X (Snow Leopard/Lion), and Windows operating systems
and the 32-bit (<code>386</code>) and 64-bit (<code>amd64</code>)
x86 processor architectures.
</p>