[Bug testsuite/65116] [4.9/5 Regression] additional_sources not defined anymore during dg-final

[mkuvyrkov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65116

--- Comment #5 from Maxim Kuvyrkov <mkuvyrkov at gcc dot gnu.org> ---
It was tested, but, obviously, not as well as it should.  I'll revert the
change for now.