[flang][NFC] Make KindTy consistent and consistently used.

[kiranchandramohan]

Should we change the following two usage as well?

lib/Optimizer/Dialect/FIRAttr.cpp:  int getFKind() const { return kind; }
lib/Optimizer/Dialect/FIRAttr.cpp:int RealAttr::getFKind() const { return getImpl()->getFKind(); }

[kiranchandramohan]

LGTM. The proposed change can be made if necessary.

[mehdi_amini]

This kind of trivial renamings seem quite straightforward: should we use post-commit review for these?

[schweitz]

In D96154#2545550, @kiranchandramohan wrote:

Should we change the following two usage as well?

lib/Optimizer/Dialect/FIRAttr.cpp:  int getFKind() const { return kind; }
lib/Optimizer/Dialect/FIRAttr.cpp:int RealAttr::getFKind() const { return getImpl()->getFKind(); }

Yes. Thanks for spotting this one.

flang/include/flang/Optimizer/Dialect/FIRType.h

 class ComplexType;
 class FloatType;
 } // namespace mlir
 
 namespace fir {
 
 class FIROpsDialect;
 
-using KindTy = int;
+using KindTy = unsigned;
 
 namespace detail {
 struct BoxTypeStorage;
 struct BoxCharTypeStorage;
 struct BoxProcTypeStorage;
 struct CharacterTypeStorage;
 struct ComplexTypeStorage;
 struct FieldTypeStorage;

flang/lib/Optimizer/Dialect/FIRType.cpp

 //===-- FIRType.cpp -------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
+//
+// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
+//
+//===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
+#include "mlir/IR/Builders.h"
 #include "mlir/IR/Diagnostics.h"
 #include "mlir/IR/DialectImplementation.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
 
 using namespace fir;

 } // namespace fir
 
 // CHARACTER
 
 CharacterType fir::CharacterType::get(mlir::MLIRContext *ctxt, KindTy kind) {
   return Base::get(ctxt, kind);
 }
 
-int fir::CharacterType::getFKind() const { return getImpl()->getFKind(); }
+KindTy fir::CharacterType::getFKind() const { return getImpl()->getFKind(); }
 
 // Field
 
 FieldType fir::FieldType::get(mlir::MLIRContext *ctxt) {
   return Base::get(ctxt, 0);
 }
 
 // Len
 
 LenType fir::LenType::get(mlir::MLIRContext *ctxt) {
   return Base::get(ctxt, 0);
 }
 
 // LOGICAL
 
 LogicalType fir::LogicalType::get(mlir::MLIRContext *ctxt, KindTy kind) {
   return Base::get(ctxt, kind);
 }
 
-int fir::LogicalType::getFKind() const { return getImpl()->getFKind(); }
+KindTy fir::LogicalType::getFKind() const { return getImpl()->getFKind(); }
 
 // INTEGER
 
 fir::IntegerType fir::IntegerType::get(mlir::MLIRContext *ctxt, KindTy kind) {
   return Base::get(ctxt, kind);
 }
 
-int fir::IntegerType::getFKind() const { return getImpl()->getFKind(); }
+KindTy fir::IntegerType::getFKind() const { return getImpl()->getFKind(); }
 
 // COMPLEX
 
 fir::ComplexType fir::ComplexType::get(mlir::MLIRContext *ctxt, KindTy kind) {
   return Base::get(ctxt, kind);
 }
 
 mlir::Type fir::ComplexType::getElementType() const {
   return fir::RealType::get(getContext(), getFKind());
 }
 
 KindTy fir::ComplexType::getFKind() const { return getImpl()->getFKind(); }
 
 // REAL
 
 RealType fir::RealType::get(mlir::MLIRContext *ctxt, KindTy kind) {
   return Base::get(ctxt, kind);
 }
 
-int fir::RealType::getFKind() const { return getImpl()->getFKind(); }
+KindTy fir::RealType::getFKind() const { return getImpl()->getFKind(); }
 
 // Box<T>
 
 BoxType fir::BoxType::get(mlir::Type elementType, mlir::AffineMapAttr map) {
   return Base::get(elementType.getContext(), elementType, map);
 }
 
 mlir::Type fir::BoxType::getEleTy() const {