i965: Make scheduler cycle estimates use the proper stage name.

i965: Make scheduler cycle estimates use the proper stage name.

Previously, the vec4 backend labeled shaders as "vec4" - now it uses the
specific names "VS" and "GS".

The FS backend now correctly prints "VS" for vertex shaders (rather than
"fs").  It also prints "FS" instead of "fs" for fragment shaders;
preserving that behavior didn't seem essential.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>