Enable Drone CI for ARM 64/32-bit cases. (#2520)

https://bugs.ruby-lang.org/issues/16234

.drone.yml

@@ -0,0 +1,65 @@
+---
+kind: pipeline
+type: docker
+name: arm64
+platform:
+  os: linux
+  arch: arm64
+steps:
+  - name: test
+    image: ruby:2.5-stretch
+    commands:
+      - uname -m
+      - apt-get -yq update
+      - apt-get -yq install software-properties-common
+      - apt-get -yq install bison sudo
+      # workaround ipv6 localhost
+      - ruby -e "hosts = File.read('/etc/hosts').sub(/^::1\s*localhost.*$/, ''); File.write('/etc/hosts', hosts)"
+      # create user
+      - useradd --shell /bin/bash --create-home test && chown -R test:test .
+      # configure
+      - /usr/bin/sudo -H -u test -- bash -c 'autoconf && ./configure --disable-install-doc --prefix=/tmp/ruby-prefix'
+      # make all install
+      - /usr/bin/sudo -H -u test -- make -j$(nproc) all install
+      # make test
+      - /usr/bin/sudo -H -u test -- make test
+      # make test-spec
+      - /usr/bin/sudo -H -u test -- make test-spec
+      # make test-all
+      - /usr/bin/sudo -H -u test -- make test-all
+# trigger:
+#   branch:
+#     - master
+
+---
+kind: pipeline
+type: docker
+name: arm32
+platform:
+  os: linux
+  arch: arm
+steps:
+  - name: test
+    image: ruby:2.5-stretch
+    commands:
+      - uname -m
+      - apt-get -yq update
+      - apt-get -yq install software-properties-common
+      - apt-get -yq install bison sudo
+      # workaround ipv6 localhost
+      - ruby -e "hosts = File.read('/etc/hosts').sub(/^::1\s*localhost.*$/, ''); File.write('/etc/hosts', hosts)"
+      # create user
+      - useradd --shell /bin/bash --create-home test && chown -R test:test .
+      # configure
+      - /usr/bin/sudo -H -u test -- bash -c 'autoconf && ./configure --disable-install-doc --prefix=/tmp/ruby-prefix'
+      # make all install
+      - /usr/bin/sudo -H -u test -- make -j$(nproc) all install
+      # make test
+      - /usr/bin/sudo -H -u test -- make test
+      # make test-spec
+      - /usr/bin/sudo -H -u test -- make test-spec
+      # make test-all
+      - /usr/bin/sudo -H -u test -- make test-all
+# trigger:
+#   branch:
+#     - master