ci: Add a build with G_DISABLE_ASSERT defined

We want GLib to build correctly with this defined, and for all its tests
to still pass.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #1708

.gitlab-ci.yml

@@ -51,6 +51,30 @@ fedora-x86_64:
       - "_build/meson-logs"
       - "_coverage"
 
+G_DISABLE_ASSERT:
+  stage: build
+  except:
+    - tags
+  variables:
+    CPPFLAGS: "-DG_DISABLE_ASSERT"
+  script:
+    - meson ${MESON_COMMON_OPTIONS}
+            --werror
+            -Dsystemtap=true
+            -Ddtrace=true
+            -Dfam=true
+            -Dinstalled_tests=true
+            _build
+    - ninja -C _build
+    - meson test -C _build --timeout-multiplier ${MESON_TEST_TIMEOUT_MULTIPLIER} --no-suite flaky
+  artifacts:
+    name: "glib-${CI_JOB_NAME}-${CI_COMMIT_REF_NAME}"
+    when: always
+    paths:
+      - "_build/config.h"
+      - "_build/glib/glibconfig.h"
+      - "_build/meson-logs"
+
 .cross-template: &cross-template
   stage: build
   except: