At least some versions of GCC put the -gsplit-dwarf .dwo file in cwd when
compiling and linking is done together in one compiler invocation, see
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90575> "-gsplit-dwarf leaves
behind .dwo file in cwd".

Change-Id: I1b418e400a3e8107997fbbfd7f87ef3ac9fbbd28
Reviewed-on: https://gerrit.libreoffice.org/72841
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>