[gimp/wip/Jehan/CI-clang] gitlab-ci: test a CLang build.

[Jehan <jehanp src gnome org>]

commit b42c6d6eb7d1fdac89c1389ae148860d39f58ed4
Author: Jehan <jehan girinstud io>
Date:   Fri Jan 3 00:19:10 2020 +0100

    gitlab-ci: test a CLang build.

 .gitlab-ci.yml | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 80bafaaeee..e7f16fca11 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -150,6 +150,19 @@ gimp-debian/testing-meson:
     - ninja -C _build
     # - ninja test
 
+gimp-debian/testing-clang:
+  extends: .gimp-debian/testing-base
+  variables:
+    CC: "clang"
+  script:
+    - meson _build
+      --prefix="${INSTALL_PREFIX}"
+      -Dpython=always
+      -Djavascript=always
+      -Dlua=always
+    - ninja -C _build
+    # - ninja test
+
 ## WINDOWS 64-bit CI ##
 
 deps-win64: