Add VK_LWIN and VK_RWIN keys as meta modifiers

Task-number: QTBUG-43163
Change-Id: Iee9bb4b48dc7ea9f806abd6b07648cce46a79b6a
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>

src/plugins/platforms/windows/qwindowskeymapper.cpp

@@ -1189,6 +1189,8 @@ Qt::KeyboardModifiers QWindowsKeyMapper::queryKeyboardModifiers()
         modifiers |= Qt::ControlModifier;
     if (GetKeyState(VK_MENU) < 0)
         modifiers |= Qt::AltModifier;
+    if (GetKeyState(VK_LWIN) < 0 || GetKeyState(VK_RWIN) < 0)
+        modifiers |= Qt::MetaModifier;
     return modifiers;
 }