If transform feedback is recording a varying, it needs a slot in the
VUE map, regardless of whether or not the shader writes it.
Together with the previous patch, this fixes:
- KHR-GL45.enhanced_layouts.xfb_capture_struct
The test captures a structure where the vertex shader writes the first
and third members - but the second still needs a slot.
Reviewed-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Kenneth Graunke
ef719f4fd2