[CI] Restructure CI to be simpler with overrides

.gitlab/ci/centos-7.yml

@@ -1,8 +1,5 @@
 include: '/.gitlab/ci/platform-test.yml'
 
-variables:
-  SWIFT_STANDARD_PLATFORM_TESTS: "false"
-
 .centos7:
   extends: .platform-test
   before_script:

.gitlab/ci/main.yml

@@ -58,38 +58,38 @@ Code Climate:
     reports:
       codequality: gl-code-quality-report.json
 
-.platform-test:
+.standard-platform-test:
   stage: Platform Tests
   trigger:
     strategy: depend
-    include: '/.gitlab/ci/platform-test.yml'
+    include: '/.gitlab/ci/standard-platforms.yml'
 
 Ubuntu Bionic:
-  extends: .platform-test
+  extends: .standard-platform-test
   variables:
     SWIFT_PLATFORM_NAME: bionic
 
 Ubuntu Xenial:
-  extends: .platform-test
+  extends: .standard-platform-test
   variables:
     SWIFT_PLATFORM_NAME: xenial
 
 Ubuntu Focal:
-  extends: .platform-test
+  extends: .standard-platform-test
   variables:
     SWIFT_PLATFORM_NAME: focal
 
 CentOS 7:
-  extends: .platform-test
+  extends: .standard-platform-test
   trigger:
     include: '/.gitlab/ci/centos-7.yml'
 
 CentOS 8:
-  extends: .platform-test
+  extends: .standard-platform-test
   variables:
     SWIFT_PLATFORM_NAME: centos8
 
 Amazon Linux 2:
-  extends: .platform-test
+  extends: .standard-platform-test
   variables:
     SWIFT_PLATFORM_NAME: amazonlinux2

.gitlab/ci/platform-test.yml

@@ -1,9 +1,6 @@
 stages:
   - Test
 
-variables:
-  SWIFT_STANDARD_PLATFORM_TESTS: "true"
-
 .platform-test:
   stage: Test
   tags:
@@ -18,25 +15,4 @@ variables:
   script:
     - swift build --build-tests --enable-test-discovery --sanitize=thread -v 
     - swift test --skip-build
-
-.standard-platform:
-  extends: .platform-test
-  rules:
-    - if: '$SWIFT_STANDARD_PLATFORM_TESTS == "true"'
-
-swift trunk:
-  extends: .standard-platform
-  image: swiftlang/swift:nightly-master-${SWIFT_PLATFORM_NAME}
-  allow_failure: true
-
-swift 5.5:
-  extends: .standard-platform
-  image: swift:5.5-${SWIFT_PLATFORM_NAME}
-
-swift 5.4:
-  extends: .standard-platform
-  image: swift:5.4-${SWIFT_PLATFORM_NAME}
-
-swift 5.3:
-  extends: .standard-platform
-  image: swift:5.3-${SWIFT_PLATFORM_NAME}
+    

.gitlab/ci/standard-platforms.yml

@@ -0,0 +1,18 @@
+include: '/.gitlab/ci/platform-test.yml'
+
+swift trunk:
+  extends: .platform-test
+  image: swiftlang/swift:nightly-master-${SWIFT_PLATFORM_NAME}
+  allow_failure: true
+
+swift 5.5:
+  extends: .platform-test
+  image: swift:5.5-${SWIFT_PLATFORM_NAME}
+
+swift 5.4:
+  extends: .platform-test
+  image: swift:5.4-${SWIFT_PLATFORM_NAME}
+
+swift 5.3:
+  extends: .platform-test
+  image: swift:5.3-${SWIFT_PLATFORM_NAME}