nir: do not vectorize load/store if offset can overflow and robustness enabled

nir: do not vectorize load/store if offset can overflow and robustness enabled

This prevents vectorization for loads/stores that can overflow if
the low offset is negative and the range greater or equal than 0.

The caller can pass the list of variable modes that matter for
robust access.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4881>