removed OsStr impls

Author: Billy-Sheppard

library/std/src/ffi/os_str.rs

@@ -1352,26 +1352,6 @@ impl Default for &OsStr {
     }
 }
 
-#[stable(feature = "more_rc_default_impls", since = "CURRENT_RUSTC_VERSION")]
-impl Default for Arc<OsStr> {
-    /// Creates an empty OsStr inside an Arc
-    #[inline]
-    fn default() -> Self {
-        let os_str: &OsStr = Default::default();
-        Arc::from(os_str)
-    }
-}
-
-#[stable(feature = "more_rc_default_impls", since = "CURRENT_RUSTC_VERSION")]
-impl Default for Rc<OsStr> {
-    /// Creates an empty OsStr inside an Rc
-    #[inline]
-    fn default() -> Self {
-        let os_str: &OsStr = Default::default();
-        Rc::from(os_str)
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl PartialEq for OsStr {
     #[inline]