Auto merge of #96802 - gimbles:windows_slice, r=thomcc

[feat] Make sys::windows::os_str::Slice repr(transparent)

Fixes #96577

Author: bors

library/std/src/sys/windows/os_str.rs

@@ -44,6 +44,7 @@ impl fmt::Display for Buf {
     }
 }
 
+#[repr(transparent)]
 pub struct Slice {
     pub inner: Wtf8,
 }