PowerPC: multiarch support for PPC32

[Adhemerval Zanella <azanella at linux dot vnet dot ibm dot com>]

Hi glibc community,

I just pushed to azanella/multilib-ppc32 branch a multilib support for PowerPC32.
Some considerations:

* The support is complete with both string/etc. and fpu specialized functions.

* Minimum architecture supported is current glibc one (basically powerpc, prior
  to POWER4).

* With the patches I pushed some common implementation to sysdeps/powerpc/powerX
  from sysdeps/powerpc/power32/.. and this required some cleanup on PowerPC64
  side.

* Each commit represent a symbol with first commit the initial support for the
  libc_ifunc mechanism, except the first one (initial support) and 20th one that
  setups the multiarch search order.

* Some cleanup was done, although mostly focused on comments.

* Current branch does not contain any ChangeLogs, but I intend to do so on patch
  posting.

The patch set is quite extensive, 37 patches with large changes, so I would ask for
recommendations is which will be the better way send the patch. Should I create
sub-messages with proper ChangeLog for each patch or should I wait for some test
with the branch?

I do not intend to push for 2.18, although I'd like some early recommendation,
advices, etc. so I could avoid pitfalls in the PowerPC64 implementation. Should I
wait to 2.18 window close before start to post patches?

I tested with GCC 4.4.6 and 4.7.3 on PowerPC32. I still running tests on different
platforms and checking if an build issue related to gcc trunk is a compiler issue
or a code one.

Thanks for your attention.