[VPlan] Strip bad assert in VPTransformState::get (NFC)

The assert only currently holds by chance, as vputils::isSingleScalar
handles a lot more recipes.

Author: artagnon

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -308,11 +308,6 @@ Value *VPTransformState::get(const VPValue *Def, bool NeedsScalar) {
   VPLane LastLane(IsSingleScalar ? 0 : VF.getFixedValue() - 1);
   // Check if there is a scalar value for the selected lane.
   if (!hasScalarValue(Def, LastLane)) {
-    // At the moment, VPWidenIntOrFpInductionRecipes, VPScalarIVStepsRecipes and
-    // VPExpandSCEVRecipes can also be a single scalar.
-    assert((isa<VPWidenIntOrFpInductionRecipe, VPScalarIVStepsRecipe,
-                VPExpandSCEVRecipe>(Def->getDefiningRecipe())) &&
-           "unexpected recipe found to be invariant");
     IsSingleScalar = true;
     LastLane = 0;
   }