glsl/glcpp: Alphabetize lists of start conditions

glsl/glcpp: Alphabetize lists of start conditions

There is no behavioral change here. It's just easier to verify that lists
of start conditions include all expected conditions when they appear in a
consistent order.

The <INITIAL> state is special, so it appears first in all lists. All others
appear in alphabetical order.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>