st/mesa: Re-assign vs in locations after updating nir info for ffvp/ARB_vp
After call to nir_shader_gather_info - inputs_read may have changed so st_nir_assign_vs_in_locations should be called for shader to remain in sync with vbo state.
Fixes piglit tests:
- gl-1.0-fpexceptions
- gl-1.1-color-material-unused-normal-array
- arb_vertex_program-unused-attributes
regression on radeonsi
Fixes: d684fb37