Fix supported archs on website

doc/index.html

@@ -103,9 +103,9 @@ net.createServer(function (socket) {
         Node is tested on <b>Linux</b>, <b>Macintosh</b>, and
         <b>Solaris</b>. It also runs on <b>Windows/Cygwin</b>,
         <b>FreeBSD</b>, and <b>OpenBSD</b>. The build system requires Python
-        2.4 or better.  V8, on which Node is built, supports only IA-32 and
-        ARM processors. V8 is included in the Node distribution. To use TLS,
-        OpenSSL is required.  There are no other dependencies.
+        2.4 or better.  V8, on which Node is built, supports only IA-32,
+        x64, and ARM processors. V8 is included in the Node distribution.
+        To use TLS, OpenSSL is required.  There are no other dependencies.
       </p>
 
       <pre class="sh_none">