qt: fix multiple compiler warnings

src/qt/qt_newfloppydialog.cpp

@@ -339,6 +339,11 @@ bool NewFloppyDialog::create86f(const QString& filename, const disk_size_t& disk
     return true;
 }
 
+/* Ignore false positive warning caused by a bug on gcc */
+#ifdef __GNUC__
+#pragma GCC diagnostic ignored "-Wstringop-overflow"
+#endif
+
 bool NewFloppyDialog::createSectorImage(const QString &filename, const disk_size_t& disk_size, FileType type)
 {
     uint32_t total_size = 0;

src/qt/qt_platform.cpp

@@ -74,11 +74,13 @@ private:
 
 extern "C" {
 #ifdef Q_OS_WINDOWS
-#define NOMINMAX
-#include <windows.h>
-#include <86box/win.h>
+#    ifndef NOMINMAX
+#        define NOMINMAX
+#    endif
+#    include <windows.h>
+#    include <86box/win.h>
 #else
-#include <strings.h>
+#    include <strings.h>
 #endif
 #include <86box/86box.h>
 #include <86box/device.h>

src/qt/qt_settings_bus_tracking.cpp

@@ -218,7 +218,7 @@ SettingsBusTracking::scsi_bus_full()
 void
 SettingsBusTracking::device_track(int set, uint8_t dev_type, int bus, int channel)
 {
-    int i, element;
+    int element;
     uint64_t mask;
     uint8_t count = 0;
 

src/qt/qt_settingsinput.cpp

@@ -54,7 +54,6 @@ void SettingsInput::onCurrentMachineChanged(int machineId) {
     // win_settings_video_proc, WM_INITDIALOG
     this->machineId = machineId;
 
-    const auto* machine = &machines[machineId];
     auto* mouseModel = ui->comboBoxMouse->model();
     auto removeRows = mouseModel->rowCount();
 

src/qt/qt_settingsnetwork.cpp

@@ -80,7 +80,6 @@ void SettingsNetwork::save() {
 
 void SettingsNetwork::onCurrentMachineChanged(int machineId) {
     this->machineId = machineId;
-    auto* machine = &machines[machineId];
 
     auto* model = ui->comboBoxAdapter->model();
     auto removeRows = model->rowCount();

src/qt/qt_settingsstoragecontrollers.cpp

@@ -64,7 +64,6 @@ void SettingsStorageControllers::save() {
 
 void SettingsStorageControllers::onCurrentMachineChanged(int machineId) {
     this->machineId = machineId;
-    auto* machine = &machines[machineId];
 
     /*HD controller config*/
     auto* model = ui->comboBoxHD->model();