[Clang][TableGen] Use PointerType::get(Context) in MVE TableGen emitter (NFC) (#124782)

Follow-up to #123569

Co-authored-by: Nikita Popov <[email protected]>

Author: junlarsen

clang/utils/TableGen/MveEmitter.cpp

@@ -209,9 +209,7 @@ class PointerType : public Type {
       Name = "const " + Name;
     return Name + " *";
   }
-  std::string llvmName() const override {
-    return "llvm::PointerType::getUnqual(" + Pointee->llvmName() + ")";
-  }
+  std::string llvmName() const override { return "Builder.getPtrTy()"; }
   const Type *getPointeeType() const { return Pointee; }
 
   static bool classof(const Type *T) {