Create a new overlay used to mark Attachment header (bug#37370)

* lisp/gnus/gnus-art.el (gnus-mime-inline-part)
(gnus-mm-display-part, gnus-mime-buttonize-attachments-in-header):
Create a new overlay used to mark Attachment header instead of
using existing overlays.
1 job for master in 53 minutes and 30 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #3246
test-all

00:53:30

 
Name Stage Failure
failed
test-all Test
make[2]: *** [check-doit] Error 1
Makefile:319: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[1]: *** [check-expensive] Error 2
Makefile:294: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1