Add OpenCL blurb to release notes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145270 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html
index 4bd5cab..d38b95e 100644
--- a/docs/ReleaseNotes.html
+++ b/docs/ReleaseNotes.html
@@ -133,6 +133,10 @@
     Objective-C runtime, or version 1.6 or later of the GNUstep Objective-C
     runtime version.</li>
 
+  <li>Improved support for OpenCL C, including the <tt>vec_step</tt> operator,
+      address space qualifiers, improved vector literal support and code
+      generation support for the <a href="#PTX">PTX target</a>.</li>
+
   <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
       interface, to improve the performance of code completion and the mapping
       from source locations to abstract syntax tree nodes.</li>