pan/bi: Add base vertex to vertex ID
Indirect path tested with piglit's arb_draw_indirect-vertexid
test. BaseVertex/BaseInstance
support tested with arb_shader_draw_parameters-*
(both the direct and indirect path).
Indirect path tested with piglit's arb_draw_indirect-vertexid
test. BaseVertex/BaseInstance
support tested with arb_shader_draw_parameters-*
(both the direct and indirect path).