Related: rhbz#1125588 force existence of argument save area

ELFv2 ABI on ppc64 optimises stack allocation
(http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01149.html
so we're getting no argument save area

This now appears to pass the simple cases and onwards
to the tricky ones

Change-Id: Ie56d148ebea7fcfc023cb7183bc97f09186e66b4