Add a vxworks build phase in gitlab CI

This platform has some special cases in the build process, so it is
safer to add a CI step for it.

The testsuite is not ready yet to test cross platforms.

Issue: eng/toolchain/gnatcoll-core#124

Author: Jicquel

.gitlab-ci.yml

@@ -193,6 +193,13 @@ build_and_test_x86_64_linux_llvm:
     BUILD_ARGS: -Qcompiler=gnat-llvm
     TEST_ARGS: -Qcompiler=gnat-llvm
 
+build_x86_64_linux_vx7r2_21.07:
+  extends: .job_template
+  stage: build
+  script:
+  - anod vcs --add-repo gnatcoll-core $CI_PROJECT_DIR
+  - anod build --latest gnatcoll-core --target=x86_64-vx7r2,21.07,,unknown
+
 build_and_test_x86_64_linux_valgrind:
   extends: .build_and_test_x86_64_linux_template
   allow_failure: true # To remove once all tests pass