[PATCH, doc] Add S/390 release notes for GCC 4.3

[Andreas Krebbel]

Hello,

the attached patch adds the release notes for S/390 to the
changes.html page for GCC 4.3.

OK to apply?

Bye,

-Andreas-

Index: htdocs/gcc-4.3/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.3/changes.html,v
retrieving revision 1.91
diff -r1.91 changes.html
754a755,787
> <h3>S/390, zSeries and System z9</h3>
>   <ul>
>     <li>Support for the IBM System z9 EC/BC processor (z9 109 GA3) has
>         been added.  When using the <code>-march=z9-ec</code> option,
>         the compiler will generate code making use of instructions
>         provided by the decimal floating point facility and the
>         floating point conversion facility (pfpo).  Besides the
>         instructions used to implement decimal floating point
>         operations these facilities also contain instructions to move
>         between general purpose and floating point registers and to
>         modify and copy the sign bit of floating point values.</li>
>     <li>When the <code>-march=z9-ec</code> option is used the new
>         <code>-mhard-dfp/-mno-hard-dfp</code> options can be used to
>         specify whether the decimal floating point hardware
>         instructions will be used or not.  If none of them is given
>         the hardware support is enabled by default.</li>
>     <li>The <code>-mstack-guard</code> option can now be ommitted when
>         using stack checking via <code>-mstack-size</code> in order to
>         let GCC choose a sensible value according to the frame size of
>         each function.</li>
>     <li>Various changes to improve performance of generated code have been
> 	implemented, including:
>       <ul>
>         <li>The condition code set by an add logical with carry
>             instruction is now available for overflow checks
>             like: <code>a + b + carry < b</code></li>
>         <li>The test data class instruction is now used to implement
>             signbit and infinity checks of binary and decimal floating
>             point numbers.</li>
>       </ul>
>     </li>
>  </ul>
>