ARM: Support loading unmarked objects from cache.

ARM now supports loading unmarked objects from
the dynamic loader cache. Unmarked objects can
be used with the hard-float or soft-float ABI.
We must support loading unmarked objects during
the transition period from a binutils that does
not mark objects to one that does mark them with
the correct ELF flags.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>