Run CMSG tests on s390x

Closes #1240.

ci/test-runner-linux

@@ -5,15 +5,6 @@ set -e
 arch=$1
 prog=$2
 
-# Skip cmsg test on linux-s390x
-# https://github.com/rust-lang/libc/issues/1240
-if [ "$arch" = "s390x" ]; then
-	progbasename=`basename $prog`
-	if [ "${progbasename%%-*}" = "cmsg" ]; then
-		exit 0
-	fi
-fi
-
 cd /qemu/init
 echo "#!/bin/sh\n/prog --color=never" > run_prog.sh
 chmod +x run_prog.sh