Add CHANGES note for [GL #2606]

diff --git a/CHANGES b/CHANGES
index 6d31e82b2f3ede92d2a8aabbbe64614a1152f41c..c6717947082c910e75d026606422f1c17e3682d5 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+5657.  [cleanup]       Removed support for builtin atomics in old versions
+                       of clang (<< 3.6.0) and gcc (<< 4.7.0), and atomics
+                       emulated with mutex. [GL #2606]
+
 5656.  [bug]           Ensure that large responses work correctly over
                        DoH, and that zone transfer requests over DoH are
                        explicitly rejected. [GL !5148]