[patch, wwwdocs] Mention POWER IEEE128 changes for gcc 12

[Thomas Koenig via Gcc-patches]

Hi,

the attached patch documents the support for IEEE long double for
Fortran.  OK?  Suggestions for better wording?

Best regards

        Thomas


Mention support for IEEE 128-bit long double for Fortran.

        * htdocs/gcc-12/changes.html: Mention support for IEEE
        128-bit long double for Fortran.
diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html
index e9f132c0..083d713e 100644
--- a/htdocs/gcc-12/changes.html
+++ b/htdocs/gcc-12/changes.html
@@ -497,6 +497,14 @@ function Multiply (S1, S2 : Sign) return Sign is
     conforming to the Fortran 2018 standard.  Previous versions
     used <code>OPERATOR</code> which conforms to TS 18508.
   </li>
+  <li>
+    On POWER systems which support it, <code>-mabi=ieeelongdouble</code>
+    now uses IEEE 128-bit for <code>REAL(KIND=16)</code>.
+    <code>R16_IBM</code> and <code>R16_IEEE</code> have been added to the
+    <code>-fconvert</code> option, the <code>CONVERT</code> specifyer of
+    the <code>OPEN</code> statement and the <code>GFORTRAN_CONVERT_UNIT</code>
+    environment variable.
+  </li>
 </ul>
 
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