llvm-project

17303290 - Revert "[VPlan] Mark Select VPInstructions as not having sideeffects."

Revert "[VPlan] Mark Select VPInstructions as not having sideeffects." This reverts commit 19918ac34dc5d304ec6ad413ceae1d4394abe28f. Fixes #75298. There is still a case where we miss the correct users outside the main vector loop for reductions, and that is tail-folded loops with reductions where the final value is stored after the loop. This should be handled explicitly in #70253