[binutils-gdb] Correct removal of .gnu.attributes

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT b8a6ced79668ec8af3180e50b76f7517ebbab0d9 ***

Author: Alan Modra <amodra@gmail.com>
Branch: master
Commit: b8a6ced79668ec8af3180e50b76f7517ebbab0d9

Correct removal of .gnu.attributes

Setting SEC_EXCLUDE for empty .gnu.attributes is too late in the link
process for the linker to remove the section.  That must be done in
bfd_elf_final_link, as we do for removed group sections.

	* elflink.c (bfd_elf_final_link): Remove zero size .gnu.attributes
	sections.