As 56f87dac says, this is about clang 9, not clang 8.

Change-Id: I2978d2235c7eb3ad438082f7b08a1bd68977ed6f
Reviewed-on: https://gerrit.libreoffice.org/72974
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>