MLBEDSW-9758: Fix negative offsets in DecomposeForStrides
Fix handling of negative offsets when rejecting slices in stride decomposition.
- Treat negative offsets as TOP/LEFT padding.
- Adjust coordinate with IfmStride to find first positive coordinate
- Determine whether first positive coordinate results in a volume
Change-Id: I2ecd5a5547f13f9efbc280339ab0e076bdce67f9 Signed-off-by: Alexander Bengtsson Alexander.Bengtsson@arm.com