[1/2] Document HLE / RTM intrinsics

[Uros Bizjak]

Hello!

> >> >From: Andi Kleen <ak@linux.intel.com>
> >>
> >> >+Returns _XBEGIN_STARTED when the transaction
> >> >+started successfully (not this is not 0, so the constant has to be
> >>
> >> not this is not 0? Or note?
> >
> > "note"
> >
> > Thanks. Will fix before comitting.
>
> I think (somewhere else) we agreed to only document intrinsics,
> not the __builtin_ia32_ variants (they are an implementation detail).
> Yes, we're not consistent with that, but we do miss a lot of
> documentation for these kind of builtins.  I suppose we also do not
> document all intrinsics either (though that's desired, as we provide
> those headers - even manpages would be nice for them I suppose).
>
> Target maintainers?

The proposed documentation does mention that these intrinsics are for
internal use only.

I think that the patch in its latest version is OK

Thanks,
Uros.