[wwwdocs] Add AVR news.

[Georg-Johann Lay]

Added the following change to the v10 changes site.

Johann

diff --git a/htdocs/gcc-10/changes.html b/htdocs/gcc-10/changes.html
index d6108269..7d96bc66 100644
--- a/htdocs/gcc-10/changes.html
+++ b/htdocs/gcc-10/changes.html
@@ -334,7 +334,54 @@ a work-in-progress.</p>
   <code>arm-uclinuxfdpiceabi</code>, and the C library is uclibc-ng.
   </li>
 </ul>
-<!-- <h3 id="avr">AVR</h3> -->
+
+<h3 id="avr">AVR</h3>
+<ul>
+  <li>Support for the XMEGA-like devices
+    <blockquote>
+      ATtiny202, ATtiny204, ATtiny402, ATtiny404, ATtiny406, ATtiny804,
+      ATtiny806, ATtiny807, ATtiny1604, ATtiny1606, ATtiny1607, ATmega808,
+      ATmega809, ATmega1608, ATmega1609, ATmega3208, ATmega3209,
+      ATmega4808, ATmega4809
+    </blockquote>
+    has been added.
+  </li>
+  <li>
+    A new command line option <code>-nodevicespecs</code> has been added.
+    It allows to provide a custom device-specs file by means of
+    <blockquote><code>
+       avr-gcc -nodevicespecs -specs=<em>my-spec-file</em> &lt;options&gt;
+    </code></blockquote>
+    and without the need to provide options <code>-B</code> and
+    <code>-mmcu=</code>.
+    See
+    <a 
href="https://gcc.gnu.org/onlinedocs/gcc/AVR-Options.html#index-nodevicespecs";>AVR
+      command line options</a> for details.
+    This feature is also available in v9.3+ and v8.4+.
+  </li>
+  <li>
+    New command line options <code>-mdouble=[32,64]</code> and
+    <code>-mlong-double=[32,64]</code> have been added.  They allow
+    to chose the size (in bits) of the <code>double</code> and
+    <code>long double</code> types, respectively.  Whether or not the
+    mentioned layouts are available, whether the options act
+    as a multilib option, and what is the default for either option
+    is controlled by the new
+    <a href="https://gcc.gnu.org/install/configure.html#avr";>AVR configure
+      options</a>
+    <code>--with-double=</code> and <code>--with-long-double=</code>.
+  </li>
+  <li>
+    A new configure option <code>--with-libf7=</code> has been added.
+    It controls to which level avr-libgcc provides 64-bit floating point
+    support by means of
+    <a href="https://gcc.gnu.org/wiki/avr-gcc#LibF7";>LibF7</a>.
+  </li>
+  <li>
+    A new configure option <code>--with-double-comparison=</code> has been
+    added. It's unlikely you need to set this option by hand.
+  </li>
+</ul>

 <!-- <h3 id="hsa">Heterogeneous Systems Architecture</h3> -->