Add release note

Author: tbaederr

clang/docs/ReleaseNotes.rst

@@ -136,6 +136,7 @@ Bug Fixes to Compiler Builtins
 
 Bug Fixes to Attribute Support
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ - Fixed crash when a parameter to the ``clang::annotate`` attribute evaluates to ``void``. See #GH119125
 
 Bug Fixes to C++ Support
 ^^^^^^^^^^^^^^^^^^^^^^^^