r600g: extract a code into a r600_emit_rasterizer_prim_state()

Also change gs_output_prim type: unsigned → pipe_prim_type. The idea of
the code is mostly taken from radeonsi. The new code operating on
prev/curr rast_primitives saves ≈15 reloads of PA_SC_LINE_STIPPLE per
frame in Kane&Lynch2

Signed-off-by: Constantine Kharlamov <Hi-Angel@yandex.ru>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
3 files changed