glx: Integer overflow protection for non-generated render requests (v3) [CVE-2014-8093 5/6]

v2:
Fix constants in __glXMap2fReqSize (Michal Srb)
Validate w/h/d for proxy targets too (Keith Packard)

v3:
Fix Map[12]Size to correctly reject order == 0 (Julien Cristau)

Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Michal Srb <msrb@suse.com>
Reviewed-by: Andy Ritger <aritger@nvidia.com>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>