[libc++] Add SHA for C++20 Synchronization Library in ABI changelog

This is mostly a means to test a new Herald rule for libc++ reviews.

Differential Revision: https://reviews.llvm.org/D76022

diff --git a/libcxx/lib/abi/CHANGELOG.TXT b/libcxx/lib/abi/CHANGELOG.TXT
index ca81722..0672fb3 100644 (file)
--- a/libcxx/lib/abi/CHANGELOG.TXT
+++ b/libcxx/lib/abi/CHANGELOG.TXT
@@ -16,7 +16,7 @@ New entries should be added directly below the "Version" header.
 Version 10.0
 ------------
 
-* TODO - [libc++] Implementation of C++20's P1135R6 for libcxx
+* 54fa9ecd3088 - [libc++] Implementation of C++20's P1135R6 for libcxx
 
   libc++ now implements P1135R6 (The C++20 Synchronization Library), which
   adds a few symbols to the dylib. This is backwards-compatible since we're