Update release note; NFC

Author: AaronBallman

clang/docs/ReleaseNotes.rst

@@ -211,8 +211,8 @@ Non-comprehensive list of changes in this release
 - Added `__builtin_elementwise_exp10`.
 - For AMDPGU targets, added `__builtin_v_cvt_off_f32_i4` that maps to the `v_cvt_off_f32_i4` instruction.
 - Added `__builtin_elementwise_minnum` and `__builtin_elementwise_maxnum`.
-- No longer crashing on invalid Objective-C extensions when dumping the AST as
-  JSON. (#GH137320)
+- No longer crashing on invalid Objective-C categories and extensions when
+  dumping the AST as JSON. (#GH137320)
 
 New Compiler Flags
 ------------------