[llvm] [VPlan] Model FOR extract of exit value in VPlan. (PR #93395)

[Florian Hahn via llvm-commits]

================
@@ -167,8 +167,8 @@ class VPLane {
 
   static VPLane getFirstLane() { return VPLane(0, VPLane::Kind::First); }
 
-  static VPLane getLastLaneForVF(const ElementCount &VF) {
-    unsigned LaneOffset = VF.getKnownMinValue() - 1;
+  static VPLane getLastLaneForVF(const ElementCount &VF, unsigned Offset = 1) {
----------------
fhahn wrote:

Generalized the patch to use ExtractFromEnd, added public `getLaneFromEnd` for that use case

https://github.com/llvm/llvm-project/pull/93395