ignore readline warnings

support-files/compiler_warnings.supp:
  readline is not maintained by us

support-files/compiler_warnings.supp

@@ -37,6 +37,11 @@ pars0lex.l: .*conversion from 'ulint' to 'int', possible loss of data.*
 db_vrfy.c : .*comparison is always false due to limited range of data type.*
 dbm.c : .*'item.dsize' is used uninitialized in this function.*
 
+#
+# readline is not maintained by us
+#
+.*/cmd-line-utils/readline/.* : .*
+
 #
 # Ignore all conversion warnings on windows 64
 # (Is safe as we are not yet supporting strings >= 2G)