mesa: fix make check for ARB_texture_gather

Clean up inconsistency in enum decoration:
- Use the undecorated enums where possible.
- MAX_PROGRAM_TEXTURE_GATHER_COMPONENTS_ARB remains decorated, since it
  has no undecorated equivalent in GL4.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70054
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
st/mesa: silence warning about unhandled enum in switch statement
r300g/swtcl: don't call draw_prepare_shader_outputs
r600g,radeonsi: create aux_context last

This fixes a regression caused by 68f6dec32ed5eede361f76c8dbdf897652659baf.
r600g: fix ínitialization of non_disp_tiling flag

This fixes a regression caused by e64633e8c3a5498998a45ab721bf80edca101cf5
draw: rename bind_sampler_states variables

Put 'fragment' in the names.  In preparation for upcoming function
renaming.
r300g: rename r300_bind_sampler_states to r300_bind_fragment_sampler_states
gallium: add pipe_context::bind_sampler_states()

The bind_vertex/geometry/fragment/compute_sampler_states() functions
will be replaced by a single functions.
cso: use pipe_context::bind_sampler_states() if non-null
draw: use pipe_context::bind_sampler_states() if non-null
util: use pipe_context::bind_sampler_states() if non-null
vl: use pipe_context::bind_sampler_states() if non-null
clover: use pipe_context::bind_sampler_states() if non-null
galahad: implement pipe_context::bind_sampler_states()
i915g: implement pipe_context::bind_sampler_states()
identity: implement pipe_context::bind_sampler_states()
ilo: implement pipe_context::bind_sampler_states()
llvmpipe: implement pipe_context::bind_sampler_states()
noop: implement pipe_context::bind_sampler_states()
rbug: implement pipe_context::bind_sampler_states()