Apply llvm fix for assertion/crash building archivers/c-blosc2
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