[SVE] Eliminate calls to default-false VectorType::get() from llvm-stress

[sdesmalen]

LGTM

llvm/tools/llvm-stress/llvm-stress.cpp

Type *pickVectorType(unsigned len = (unsigned)-1) {
 
     // Vectors of x86mmx are illegal; keep trying till we get something else.
     do {
       Ty = pickScalarType();
     } while (Ty->isX86_MMXTy());
 
     if (len != (unsigned)-1)
       width = len;
-    return VectorType::get(Ty, width);
+    return FixedVectorType::get(Ty, width);
   }
 
   /// Pick a random scalar type.
   Type *pickScalarType() {
     static std::vector<Type*> ScalarTypes;
     if (ScalarTypes.empty()) {
       ScalarTypes.assign({
         Type::getInt1Ty(Context),
void Act() override {
     // Try a bunch of different select configuration until a valid one is found.
     Value *Val0 = getRandomVal();
     Value *Val1 = getRandomValue(Val0->getType());
 
     Type *CondTy = Type::getInt1Ty(Context);
 
     // If the value type is a vector, and we allow vector select, then in 50%
     // of the cases generate a vector select.
-    if (Val0->getType()->isVectorTy() && (getRandom() % 1)) {
-      unsigned NumElem = cast<VectorType>(Val0->getType())->getNumElements();
-      CondTy = VectorType::get(CondTy, NumElem);
+    if (isa<FixedVectorType>(Val0->getType()) && (getRandom() % 1)) {
+      unsigned NumElem =
+          cast<FixedVectorType>(Val0->getType())->getNumElements();
+      CondTy = FixedVectorType::get(CondTy, NumElem);
     }
 
     Value *Cond = getRandomValue(CondTy);
     Value *V = SelectInst::Create(Cond, Val0, Val1, "Sl", BB->getTerminator());
     return PT->push_back(V);
   }
 };