[llvm] [VPlan] Add VPIRInstruction, use for exit block live-outs. (PR #100735)

[via llvm-commits]

================
@@ -8695,17 +8698,18 @@ addUsersInExitBlock(VPlan &Plan,
   }
 
   // Introduce VPUsers modeling the exit values.
-  for (const auto &[ExitPhi, V] : ExitingValuesToFix) {
+  for (const auto &[IR, V] : ExitingValuesToFix) {
     // Pass live-in values used by exit phis directly through to the live-out.
----------------
ayalz wrote:

Agreed, optimizing away redundant phi's in exit block that are fed by live-in values which bypass the original loop, and which do not qualify as lcssa phi's, best be done before LV, which relies on (proper) lcssa form.

https://github.com/llvm/llvm-project/pull/100735