ci: try to improve meson's junit.xml

GitLab doesn't show the <system-*> tags, so let's replace them.
For now it's just hacky sed; I can't use xsltproc or similar.

.gitlab-ci.yml

@@ -73,6 +73,8 @@ stages:
       - build_dist/meson-dist/*.tar.xz
     reports:
       junit: build_ci*/meson-logs/testlog.junit.xml
+  after_script:
+    - ci/fix-meson-junit.sh build_ci*/meson-logs/testlog.junit.xml
 
 archive:
   <<: *build

ci/fix-meson-junit.sh

+#!/bin/sh
+sed 's|</testcase>|</testcase>\n|g' -i "$@"
+sed -e '/<failure \/>/,/<\/testcase>/s/<\(\/\?\)system-\(out\|err\)>/<\1failure>/g' \
+	-e 's/<failure \/>//g' \
+	-i "$@"