fix command key event left and right reverse on macOS (#810)

* fix command key event left and right reverse on macOS

https://github.com/tomaka/winit/issues/808

* update changelog

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
 - On Windows, fix `CursorMoved(0, 0)` getting dispatched on window focus.
+- On macOS, fix command key event left and right reverse.
 - On FreeBSD, NetBSD, and OpenBSD, fix build of X11 backend.
 
 # Version 0.19.0 (2019-03-06)

src/platform/macos/events_loop.rs

@@ -660,8 +660,8 @@ pub fn scancode_to_keycode(code: c_ushort) -> Option<events::VirtualKeyCode> {
         0x33 => events::VirtualKeyCode::Back,
         //0x34 => unkown,
         0x35 => events::VirtualKeyCode::Escape,
-        0x36 => events::VirtualKeyCode::LWin,
-        0x37 => events::VirtualKeyCode::RWin,
+        0x36 => events::VirtualKeyCode::RWin,
+        0x37 => events::VirtualKeyCode::LWin,
         0x38 => events::VirtualKeyCode::LShift,
         //0x39 => Caps lock,
         0x3a => events::VirtualKeyCode::LAlt,