iOS: Support putting UI next to the dynamic island (emilk#5211)

winit::Window::inner_size returns size of safe area on iOS. use
winit::Window::outer_size on iOS
The dimensions of outer_size include the title bar and borders, but as
far as I know there is no way to actually display the title bar or
borders on iOS so it should be fine.

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* Closes emilk#3547 
* [X] I have followed the instructions in the PR template

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Co-authored-by: Emil Ernerfeldt <[email protected]>

crates/egui-winit/src/lib.rs

@@ -36,7 +36,14 @@ use winit::{
 };
 
 pub fn screen_size_in_pixels(window: &Window) -> egui::Vec2 {
-    let size = window.inner_size();
+    let size = if cfg!(target_os = "ios") {
+        // `outer_size` Includes the area behind the "dynamic island".
+        // It is up to the eframe user to make sure the dynamic island doesn't cover anything important.
+        // That will be easier once https://github.com/rust-windowing/winit/pull/3890 lands
+        window.outer_size()
+    } else {
+        window.inner_size()
+    };
     egui::vec2(size.width as f32, size.height as f32)
 }