Auto merge of rust-lang#23372 - tamird:fix-ios-compilation, r=alexcrichton

r? @alexcrichton cc @vhbit

Author: bors

src/libstd/sys/unix/backtrace.rs

@@ -118,7 +118,7 @@ pub fn write(w: &mut Write) -> io::Result<()> {
     // local, it still displays much nicer backtraces when a
     // couple of tasks panic simultaneously
     static LOCK: StaticMutex = MUTEX_INIT;
-    let _g = unsafe { LOCK.lock() };
+    let _g = LOCK.lock();
 
     try!(writeln!(w, "stack backtrace:"));
     // 100 lines should be enough

src/libstd/sys/unix/tty.rs

@@ -23,6 +23,8 @@ pub struct TTY {
 }
 
 #[cfg(any(target_os = "macos",
+          target_os = "ios",
+          target_os = "dragonfly",
           target_os = "freebsd",
           target_os = "bitrig",
           target_os = "openbsd"))]
@@ -54,12 +56,6 @@ impl TTY {
         Err(sys_common::unimpl())
     }
 
-    #[cfg(any(target_os = "linux",
-              target_os = "android",
-              target_os = "macos",
-              target_os = "freebsd",
-              target_os = "bitrig",
-              target_os = "openbsd"))]
     pub fn get_winsize(&mut self) -> IoResult<(int, int)> {
         unsafe {
             #[repr(C)]
@@ -82,10 +78,4 @@ impl TTY {
             }
         }
     }
-
-    #[cfg(any(target_os = "ios",
-              target_os = "dragonfly"))]
-    pub fn get_winsize(&mut self) -> IoResult<(int, int)> {
-        Err(sys_common::unimpl())
-    }
 }