The calls to upper_bound in SwDoc::FldsToExpand and SwDoc::FldsToCalc
unfortunately compare the pointers and not the values pointed to,
which causes all sorts of trouble around non-updated fields.
(regression from 2815396a)

Conflicts:
	sw/source/core/doc/docfld.cxx

Change-Id: I48817247719671a16821fcb851b17b628c960a66
(cherry picked from commit 9ca5383a)
Reviewed-on: https://gerrit.libreoffice.org/2504Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Miklos Vajna <vmiklos@suse.cz>