The array index value is a signed integer but the compiler was using
the unsigned version of the clamp helper function meaning the value
was not been clamped to 0 when its value was < 0.
Fix the following deqp test cases when shaderImageGatherExtended is enabled
dEQP-VK.glsl.texture_gather.basic.2d_array.*
dEQP-VK.glsl.texture_gather.offset.*.2d_array.*
dEQP-VK.glsl.texture_gather.offset_dynamic.*.2d_array.*
dEQP-VK.glsl.texture_gather.offsets.*.2d_array.*
Fixes: 854563f0f8 ("pco: fully switch over to common smp emission code")
Signed-off-by: Nick Hamilton <nick.hamilton@imgtec.com>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
(cherry picked from commit b80a5f9b7d)
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41268>
a3e7443e0c