object attributes v2 test woes

[Alan Modra]

Tested at commit 25bb742bc1

csky-linux-gnu breaks all over the place with
assertion fail bfd/elf-attrs.c:2515

Then there are these testsuite failures.
arm-vxworks  +FAIL: GNU attributes v1/v2: no support for directive .gnu_attribute
mips-vxworks  +FAIL: GNU attributes v1/v2: no support for directive .gnu_attribute
powerpc-wrs-vxworks  +FAIL: GNU attributes v1/v2: no support for directive .gnu_attribute
sparc-vxworks  +FAIL: GNU attributes v1/v2: no support for directive .gnu_attribute

I'm sure the guilty parties know who they are. ;-)  Please fix.

-- 
Alan Modra