V4: [PATCH] x86: Install <sys/platform/x86.h> [BZ #26124]

[Joseph Myers]

On Wed, 24 Jun 2020, Adhemerval Zanella via Libc-alpha wrote:

> Should we provide it only for __USE_GNU (_GNU_SOURCE)? And I guess that cpuid
> is not expected to be extendable. The macro API is not my favorite way of 
> doing it, but it looks ok.

The proposed header is glibc-specific.  Having __USE_GNU conditionals in 
such headers is questionable.

-- 
Joseph S. Myers
joseph@codesourcery.com