mesa: Add constants for the GL_QUERY_COUNTER_BITS per target.

mesa: Add constants for the GL_QUERY_COUNTER_BITS per target.

Drivers need to be able to communicate their actual number of bits populated
in the field in order for applications to be able to properly handle rollover.

There's a small behavior change here: Instead of reporting the
GL_SAMPLES_PASSED bits for GL_ANY_SAMPLES_PASSED (which would also be valid),
just return 1, because more bits don't make any sense.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Brian Paul <brianp@vmware.com>