[FOLD] add release note

Author: sdkrystian

clang/docs/ReleaseNotes.rst

@@ -111,6 +111,13 @@ Clang Frontend Potentially Breaking Changes
     $ clang --target=<your target triple> -print-target-triple
     <the normalized target triple>
 
+- The ``getTypeAsWritten`` member function has been removed from ``ClassTemplateSpecializationDecl`` and
+  ``VarTemplateSpecializationDecl``, and a new member function ``getTemplateArgsAsWritten`` returning a
+  ``const ASTTemplateArgumentListInfo *`` has been added to access to the explicitly written template
+  argument list of explicit specializations, partial specializations, and explicit instantiations of
+  class and variable templates. Consequently, the ``hasTypeLoc`` AST matcher will no longer match these
+  declarations and existing uses should switch to ``TemplateArgumentLoc`` matchers instead.
+
 What's New in Clang |release|?
 ==============================
 Some of the major new features and improvements to Clang are listed