Add CI for nightly trunk images of new linux platforms

Author: Mordil

.gitlab/ci/amazonlinux-2.yml

@@ -0,0 +1,6 @@
+include: '/.gitlab/ci/test-template.yml'
+
+swift trunk:
+  extends: .unit-test
+  image: swiftlang/swift:nightly-master-amazonlinux2
+  allow_failure: true

.gitlab/ci/centos-8.yml

@@ -0,0 +1,6 @@
+include: '/.gitlab/ci/test-template.yml'
+
+swift trunk:
+  extends: .unit-test
+  image: swiftlang/swift:nightly-master-centos8
+  allow_failure: true

.gitlab/ci/main.yml

@@ -69,3 +69,21 @@ Ubuntu Xenial:
   trigger:
     strategy: depend
     include: '/.gitlab/ci/ubuntu-xenial.yml'
+
+Ubuntu Focal:
+  stage: Platform Tests
+  trigger:
+    strategy: depend
+    include: '/.gitlab/ci/ubuntu-focal.yml'
+
+CentOS 8:
+  stage: Platform Tests
+  trigger:
+    strategy: depend
+    include: '/.gitlab/ci/centos-8.yml'
+
+Amazon Linux 2:
+  stage: Platform Tests
+  trigger:
+    strategy: depend
+    include: '/.gitlab/ci/amazonlinux-2.yml'

.gitlab/ci/ubuntu-focal.yml

@@ -0,0 +1,6 @@
+include: '/.gitlab/ci/test-template.yml'
+
+swift trunk:
+  extends: .unit-test
+  image: swiftlang/swift:nightly-master-focal
+  allow_failure: true