Chore: Enable warnings as errors on MSVC (#6456)

* tests: add Sanity test for SplitFilename83

fix test

fix test

* disable `C4715:not all control paths return a value` for nihstro includes

nihstro: no warn

* Chore: Enable warnings as errors on msvc + fix warnings

fixes

some more warnings

clang-format

* more fixes

* Externals: Add target_compile_options `/W0` nihstro-headers and ...

Revert "disable `C4715:not all control paths return a value` for nihstro includes"
This reverts commit 606d79b55d3044b744fb835025b8eb0f4ea5b757.

* src\citra\config.cpp: ReadSetting: simplify type casting

* settings.cpp: Get*Name: remove superflous logs

src/citra_qt/bootmanager.cpp

@@ -338,6 +338,7 @@ struct SoftwareRenderWidget : public RenderWidget {
                     case GPU::Regs::PixelFormat::RGBA4:
                         return Common::Color::DecodeRGBA4(pixel);
                     }
+                    UNREACHABLE();
                 }();
 
                 image.setPixel(x, y, qRgba(color.r(), color.g(), color.b(), color.a()));

src/citra_qt/configuration/configuration_shared.h

@@ -6,6 +6,7 @@
 
 #include <QCheckBox>
 #include <QComboBox>
+#include "common/assert.h"
 #include "common/settings.h"
 
 namespace ConfigurationShared {
@@ -91,6 +92,7 @@ Type GetComboboxSetting(int index, const Settings::SwitchableSetting<Type, range
             return static_cast<Type>(index - ConfigurationShared::USE_GLOBAL_OFFSET);
         }
     }
+    UNREACHABLE();
 }
 
 /// Given a Qt widget sets the background color to indicate whether the setting

src/citra_qt/game_list.cpp

@@ -623,8 +623,10 @@ void GameList::AddCustomDirPopup(QMenu& context_menu, QModelIndex selected) {
 void GameList::AddPermDirPopup(QMenu& context_menu, QModelIndex selected) {
     const int game_dir_index = selected.data(GameListDir::GameDirRole).toInt();
 
-    QAction* move_up = context_menu.addAction(tr("\u25b2 Move Up"));
-    QAction* move_down = context_menu.addAction(tr("\u25bc Move Down "));
+    QAction* move_up =
+        context_menu.addAction(tr("Move Up").prepend(QString::fromWCharArray(L"\u25b2 ")));
+    QAction* move_down =
+        context_menu.addAction(tr("Move Down").prepend(QString::fromWCharArray(L"\u25bc ")));
     QAction* open_directory_location = context_menu.addAction(tr("Open Directory Location"));
 
     const int row = selected.row();

src/citra_qt/main.cpp

@@ -2287,7 +2287,8 @@ void GMainWindow::UpdateBootHomeMenuState() {
     for (u32 region = 0; region < Core::NUM_SYSTEM_TITLE_REGIONS; region++) {
         const auto path = Core::GetHomeMenuNcchPath(region);
         ui->menu_Boot_Home_Menu->actions().at(region)->setEnabled(
-            (current_region == Settings::REGION_VALUE_AUTO_SELECT || current_region == region) &&
+            (current_region == Settings::REGION_VALUE_AUTO_SELECT ||
+             current_region == static_cast<int>(region)) &&
             !path.empty() && FileUtil::Exists(path));
     }
 }