MDEV-10218 - rpl.rpl_binlog_errors fails in buildbot with valgrind warnings -

             bytes are possibly lost

Restored suppressions removed by MDEV-9994: they're needed for detached threads.

mysql-test/valgrind.supp

@@ -1047,3 +1047,22 @@
    fun:_nss_dns_gethostbyaddr_r
    fun:gethostbyaddr_r
 }
+
+
+#
+# Detached threads may not complete deiniitialization by the time shutdown
+# thread calls exit. This is unfortunate property of detached threads, which
+# we currently can only ignore. Unfortunately there is no way to distinguish
+# between false positives generated by detached threads and real memory leaks
+# generated by not joined joinable threads. So we hide both cases.
+#
+# To avoid enumeration of the whole variety of possible traces we ignore all
+# "possibly lost" blocks allocated by pthread_create (and it's callees).
+#
+{
+   Detached threads memory loss
+   Memcheck:Leak
+   match-leak-kinds:possible
+   ...
+   fun:pthread_create*
+}