Merge #17591: ci: Add big endian platform - s390x

da1f153e5e260f1744ee1bf4f24ca3a74ffea465 Add s390x tests to travis (Elichai Turkel)
2fa65e0de94f01d502e8ace89be3c5dc963dd764 Add ci script to install on s390x (Elichai Turkel)

Pull request description:

  Discovered this as part of #17402 and a conversation with gmaxwell.

  You can see here that the platform is indeed BE: https://travis-ci.org/elichai/bitcoin/jobs/616656410#L36

  This closes https://github.com/bitcoin/bitcoin/issues/6466

ACKs for top commit:
  MarcoFalke:
    ACK da1f153e5e260f1744ee1bf4f24ca3a74ffea465

Tree-SHA512: e7e94e54e220257d91b24fddc79eab2bcaaadf0b2d1e7e6872d9757808ab2541728f00b1f3ab7e343305c0e7d91bb48a17a3f9621f6fff6c9fe6cde6682de408

.travis.yml

@@ -229,6 +229,12 @@ after_success:
       env: >-
         FILE_ENV="./ci/test/00_setup_env_arm.sh"
 
+    - stage: test
+      name: 'S390x  [GOAL: install]  [unit tests, functional tests]'
+      arch: s390x
+      env: >-
+        FILE_ENV="./ci/test/00_setup_env_s390x.sh"
+
     - stage: test
       name: 'Win64  [GOAL: deploy]  [unit tests, no gui, no functional tests]'
       env: >-

ci/test/00_setup_env_s390x.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+export LC_ALL=C.UTF-8
+
+export HOST=s390x-unknown-linux-gnu
+export DOCKER_NAME_TAG=s390x/ubuntu:18.04
+export PACKAGES="clang llvm python3-zmq qtbase5-dev qttools5-dev-tools libssl1.0-dev libevent-dev bsdmainutils libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-test-dev libboost-thread-dev libdb5.3++-dev libminiupnpc-dev libzmq3-dev libqrencode-dev"
+export NO_DEPENDS=1
+export RUN_UNIT_TESTS=true
+export RUN_FUNCTIONAL_TESTS=false
+export GOAL="install"
+export BITCOIN_CONFIG="--enable-reduce-exports --with-incompatible-bdb"
+
+lscpu