[PATCH] Export AT_HWCAP from libc, v4

[David Miller]

From: Richard Henderson <rth@redhat.com>
Date: Thu, 17 May 2012 09:44:50 -0700

> Changes v3->v4:
>   * Drop gethwcap in favour of only getauxval with a special case test.
> 
>     I'm just about convinced it's much more useful to extend Dave's Sparc
>     IFUNC trick to "all" targets.  I will attempt to measure this overhead
>     before I formally propose such a patch.
> 
>   * Comments updated, as per AJ.
>   * Documentation added, as per Joseph.
>   * Patch set compressed to a single patch.

These changes look good to me.

Ignore my comments about using uint64_t for hwcap, I can't do that on
sparc because on 32-bit we wouldn't be able to pass that many bits in
via the existing single hwcap aux vector anyways :-/ I'll have to
either conserve bits or pass things in via another aux vector entry,
the latter of which seems very undesirable.