Ignore text in KeyPressed with private use chars

Apparently, macOS likes to use these for simple keys.

winit/src/conversion.rs

@@ -224,7 +224,7 @@ pub fn window_event(
                     // TODO: Fix inconsistent API on Wasm
                     event.text
                 }
-            };
+            }.filter(|text| !text.as_str().chars().any(is_private_use));
 
             let winit::event::KeyEvent {
                 state, location, ..
@@ -839,3 +839,8 @@ pub fn icon(icon: window::Icon) -> Option<winit::window::Icon> {
 
     winit::window::Icon::from_rgba(pixels, size.width, size.height).ok()
 }
+
+// See: https://en.wikipedia.org/wiki/Private_Use_Areas
+fn is_private_use(c: char) -> bool {
+    c >= '\u{E000}' && c <= '\u{F8FF}'
+}