zink: Fix spirv stream 0 vertex emit for multistream shaders

zink: Fix spirv stream 0 vertex emit for multistream shaders

Spirv spec does not allow the use of OpEmitVertex or OpEndPrimitive when there are multiple streams.
Instead emit the multi-stream version of these with stream set to 0.
This issue was seen when testing cts case KHR-GL46.transform_feedback.draw_xfb_stream_test

Fixes: 35e346f4280 ("zink: handle vertex streams")
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17513>