[ReleaseNotes] Added bullet point stating that APFloat::isNormal() is now IEEE 754R-2008 compliant and that the relevant method renaming occurred.

For more information see r184449, r184350, r184356, r184366.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184452 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index ba23543..a12aaa2 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -46,6 +46,10 @@
 
 * The R600 backend is not marked experimental anymore and is built by default.
 
+* APFloat::isNormal() was renamed to APFloat::isFiniteNonZero() and
+  APFloat::isIEEENormal() was renamed to APFloat::isNormal(). This ensures that
+  APFloat::isNormal() conforms to IEEE-754R-2008.
+
 * ... next change ...
 
 .. NOTE