After 3ecd357d81, it may be possible for
the VS to get assigned all of the URB space.
On Ivy Bridge, this will cause the offset for the other stages to be
16, which cannot be packed into the ConstantBufferOffset field of
3DSTATE_PUSH_CONSTANT_ALLOC_*.
Instead we can set the offset to zero if the stage size is zero.
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Rather than keeping separate {vs,hs,ds,gs}_start fields, we now store an
array indexed by the shader stage (MESA_SHADER_*). The 3DSTATE_URB_*
commands are also sequentially numbered. This makes it easy to just
emit them in a loop.
This simplifies the code a little, and also will make it easier to add
more credible HS and DS code later.
