In case a new gl_PointCoord shader input is created, increment shader
input count and set valid driver_location to the new input variable,
otherwise the input gets aliased to input 0 and shows up in NIR_PRINT
output as whatever shader input 0 is instead of gl_PointCoord. Also
set the input as used, otherwise it might get removed.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9214>