i965: Add ARB_get_program_binary support using nir_serialization

i965: Add ARB_get_program_binary support using nir_serialization

This resolves an apparent game bug described in 85564. The game
doesn't properly handle ARB_get_program_binary with 0 supported
formats.

V2 (Timothy Arceri):
 - less driver code as more has been moved into the common helpers.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85564
Signed-off-by: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> (v1)
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>