Note on new type legalizer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65446 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index d89cab2..e1c62c9 100644
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+++ b/docs/ReleaseNotes.html
@@ -306,6 +306,15 @@
 faster:</p>
 
 <ul>
+<li>The type legalization logic has been completely rewritten, and is now
+more powerful (it supports arbitrary precision integer types for example)
+and hopefully more correct.
+The type legalizer converts operations on types that are not natively
+supported by the target machine into equivalent code sequences that only use
+natively supported types.
+The old type legalizer is still available and will be used if
+<tt>-disable-legalize-types</tt> is passed to <tt>llc</tt>.
+</li>
 <li>?</li>
 
 </ul>