Add additional test and update release notes

Author: AaronBallman

clang/docs/ReleaseNotes.rst

@@ -333,6 +333,9 @@ Bug Fixes in This Version
 - Fixed a problematic case with recursive deserialization within ``FinishedDeserializing()`` where
   ``PassInterestingDeclsToConsumer()`` was called before the declarations were safe to be passed. (#GH129982)
 - Fixed a modules crash where an explicit Constructor was deserialized. (#GH132794)
+- Defining an integer literal suffix (e.g., ``LL``) before including
+  ``<stdint.h>`` in a freestanding build no longer causes invalid token pasting
+  when using the ``INTn_C`` macros. (#GH85995)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/test/Preprocessor/stdint.c

@@ -1644,6 +1644,7 @@
 // it will not interfere with the definitions in stdint.h due to invalid tokens
 // formed via token pasting. See GH85995 for details.
 #define L %
+#define U %
 #define UL %
 #define LL %
 #define ULL %