Update changelog.

Author: scoder

CHANGES.rst

@@ -11,6 +11,9 @@ Bugs fixed
 * Cython generated incorrect self-casts when directly calling final methods of subtypes.
   Patch by Lisandro Dalcin.  (Github issue :issue:`2747`)
 
+* Internal C names generated from C function signatures could become too long for MSVC.
+  (Github issue :issue:`6052`)
+
 * The ``noexcept`` warnings could be misleading in some cases.
   Patch by Gonzalo Tornaría.  (Github issue :issue:`6087`)