Reland Remove unused header includes.
Add header includes that are needed, but previously were pulled in
transitively.
#include "llvm/Support/RISCVVIntrinsicUtils.h"
#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/Twine.h"
-#include "llvm/TableGen/Error.h"
-#include "llvm/TableGen/Record.h"
+#include "llvm/Support/raw_ostream.h"
#include <numeric>
namespace llvm {