add some upgrading notes from Pekka.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57480 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index 9aea45e..6479a27 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -480,6 +480,12 @@
 <li>Various header files like "llvm/ADT/iterator" were given a .h suffix.
     Change your code to #include "llvm/ADT/iterator.h" instead.</li>
 
+<li>In the code generator, many MachineOperand predicates were renamed to be
+    shorter (e.g. <tt>isFrameIndex()</tt> -&gt; <tt>isFI()</tt>),
+    <tt>SDOperand</tt> was renamed to <tt>SDValue</tt> (and the "<tt>Val</tt>"
+    member was changed to be the <tt>getNode()</tt> accessor), and the
+    <tt>MVT::ValueType</tt> enum has been replaced with an "<tt>MVT</tt>"
+    struct.</li>
 </ul>
 
 </div>