[C++20] [Coroutines] Add ReleaseNotes about addressing thread identifiaction problems

The thread identification problems in coroutines are addressed now in
1cedc51. Although the original problem occurs in
LLVM optimizer. The C++ users have strong feeling about it. So it may be
necessary to add a ReleaseNote in clang for it.

Closes #47177
Closes #47179

Author: ChuanqiXu9

clang/docs/ReleaseNotes.rst

@@ -248,6 +248,9 @@ Bug Fixes
   not satisfied in the event of an instantiation failures in a requires expression's
   parameter list. We previously handled this correctly in a constraint evaluation
   context, but not in a requires clause evaluated as a boolean.
+- Address the thread identification problems in coroutines.
+  `Issue 47177 <https://github.com/llvm/llvm-project/issues/47177>`_
+  `Issue 47179 <https://github.com/llvm/llvm-project/issues/47179>`_
 
 Improvements to Clang's diagnostics
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^