Scans
This adds supports for lowering scans into realize_reduction.
- Currently, scans are lowered through expression substitution. I think we came to a conclusion that the scan iname should be renamed within any instructions that it drags along. So the part of the code that is responsible for the substitution needs reworking or a bug filed against it.
- For this merge request I have set
automatic_scans_ok=False
, since we don't have full support for determining if converting a triangular reduction to a scan is "safe", since we have no code that verifies that the expression being scanned over is independent of the sweep iname. - There a couple of FIXMEs in the code left....