test drive the new bin/find-unneeded-includes --fwdecl mode
with iwyu 0.23 instead of 0.21, this seems to find more unneeded
fw declarations
Change-Id: I451e571c70eb74f46c799753e3c5a53c0110da36
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/179707
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Gabor Kelemen
de8b935e16