[VPlan] Handle VPDerivedIV and more VPInsts in isUniformAfterVector.

In preparation for re-landing
#112147, also consider
VPDerivedIVRecipe and VPInstructions with binary opcodes and PtrAdd with
all uniform operands as uniform themselves.

Effectively NFC, but will be exercised once #112147 re-lands.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlanUtils.h

@@ -48,7 +48,13 @@ inline bool isUniformAfterVectorization(const VPValue *VPV) {
   if (auto *GEP = dyn_cast<VPWidenGEPRecipe>(Def))
     return all_of(GEP->operands(), isUniformAfterVectorization);
   if (auto *VPI = dyn_cast<VPInstruction>(Def))
-    return VPI->isSingleScalar() || VPI->isVectorToScalar();
+    return VPI->isSingleScalar() || VPI->isVectorToScalar() ||
+           ((Instruction::isBinaryOp(VPI->getOpcode()) ||
+             VPI->getOpcode() == VPInstruction::PtrAdd) &&
+            all_of(VPI->operands(), isUniformAfterVectorization));
+  if (auto *IV = dyn_cast<VPDerivedIVRecipe>(Def))
+    return all_of(IV->operands(), isUniformAfterVectorization);
+
   // VPExpandSCEVRecipes must be placed in the entry and are alway uniform.
   return isa<VPExpandSCEVRecipe>(Def);
 }