Do not use TYPE_CANONICAL in useless_type_conversion

[Jan Hubicka]

> On Oct 13, 2015, Eric Botcazou <ebotcazou@adacore.com> wrote:
> 
> > Note that this is PR middle-end/67912.
> 
> Thanks.  I added this piece of information to the ChangeLog entry, and
> checked the patch in.
Thanks, Alexandre. That indeed looks better than my variant of the patch.
Does it also fix the IA-64 issue?

Honza
> 
> -- 
> Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
> You must be the change you wish to see in the world. -- Gandhi
> Be Free! -- http://FSFLA.org/   FSF Latin America board member
> Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer