Merge commit 88ce403c6aab from llvm git (by Florian Hahn):
[LV] Add new block to place recurrence splice, if needed.
In some cases, a recurrence splice instructions needs to be inserted
between to regions, for example if the regions get re-arranged during
sinking.
Fixes#56146.
PR: 264979
Reported by: Robert Clausecker <fuz@fuz.su>
MFC after: 3 days