[LV] Move optimized IV recipes to phi section of header after sinking.

Unfortunately sinking recipes for first-order recurrences relies on
the original position of recipes. So if a recipes needs to be sunk after
an optimized induction, it needs to stay in the original position, until
sinking is done. This is causing PR52460.

To fix the crash, keep the recipes in the original position until
sink-after is done.

Post-commit follow-up to c45045bf to address PR52460.