[flang] Inherit target specific code for BIND(C) types on Windows

Inherit target specific code for Windows i386 and x86_64 from the classes that
define that code for the respective processors on non-Windows operating
systems.
Only overload parts that differ.

That allows re-using the existing implementation for BIND(C) types on
non-Windows x86_64 also for Windows x86_64 targets.

Fixes #114035.

Author: mmuetzel

flang/lib/Optimizer/CodeGen/Target.cpp

@@ -199,10 +199,8 @@ struct TargetI386 : public GenericTarget<TargetI386> {
 //===----------------------------------------------------------------------===//
 
 namespace {
-struct TargetI386Win : public GenericTarget<TargetI386Win> {
-  using GenericTarget::GenericTarget;
-
-  static constexpr int defaultWidth = 32;
+struct TargetI386Win : public TargetI386 {
+  using TargetI386::TargetI386;
 
   CodeGenSpecifics::Marshalling
   complexArgumentType(mlir::Location loc, mlir::Type eleTy) const override {
@@ -718,10 +716,8 @@ struct TargetX86_64 : public GenericTarget<TargetX86_64> {
 //===----------------------------------------------------------------------===//
 
 namespace {
-struct TargetX86_64Win : public GenericTarget<TargetX86_64Win> {
-  using GenericTarget::GenericTarget;
-
-  static constexpr int defaultWidth = 64;
+struct TargetX86_64Win : public TargetX86_64 {
+  using TargetX86_64::TargetX86_64;
 
   CodeGenSpecifics::Marshalling
   complexArgumentType(mlir::Location loc, mlir::Type eleTy) const override {

flang/test/Fir/struct-passing-x86-64-several-fields-inreg.fir

@@ -2,6 +2,7 @@
 // struct has more than one field.
 // REQUIRES: x86-registered-target
 // RUN: fir-opt -target-rewrite="target=x86_64-unknown-linux-gnu" %s -o - | FileCheck %s
+// RUN: fir-opt -target-rewrite="target=x86_64-w64-windows-gnu" %s -o - | FileCheck %s
 
 
 module attributes {fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.data_layout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128", llvm.target_triple = "x86_64-unknown-linux-gnu"} {

flang/test/Fir/target-rewrite-boxchar.fir

@@ -1,5 +1,6 @@
 // RUN: fir-opt --target-rewrite="target=i386-unknown-linux-gnu" %s | FileCheck %s --check-prefix=INT32
 // RUN: fir-opt --target-rewrite="target=x86_64-unknown-linux-gnu" %s | FileCheck %s --check-prefix=INT64
+// RUN: fir-opt --target-rewrite="target=x86_64-w64-windows-gnu" %s | FileCheck %s --check-prefix=INT64
 // RUN: fir-opt --target-rewrite="target=aarch64-unknown-linux-gnu" %s | FileCheck %s --check-prefix=INT64
 // RUN: fir-opt --target-rewrite="target=powerpc64le-unknown-linux-gnu" %s | FileCheck %s --check-prefix=INT64
 // RUN: fir-opt --target-rewrite="target=amdgcn-amd-amdhsa" %s | FileCheck %s --check-prefix=INT64