mpv: fix build on darwin

diff --git a/osdep/mac/input_helper.swift b/osdep/mac/input_helper.swift

index 0acec6bd40..0ec5837864 100644

--- a/osdep/mac/input_helper.swift

+++ b/osdep/mac/input_helper.swift

@@ -18,6 +18,14 @@

 import Cocoa

 import Carbon.HIToolbox

+extension NSCondition {

+    fileprivate func withLock<T>(_ body: () throws -> T) rethrows -> T {

+        self.lock()

+        defer { self.unlock() }

+        return try body()

+    }

+}

+

 class InputHelper: NSObject {

     var option: OptionHelper?

     var lock = NSCondition()

    hash = "sha256-BOGh+QBTO7hrHohh+RqjSF8eHQH8jVBPjG/k4eyFaaM=";

  };

  patches = [

    # Fix build with Darwin SDK 11

    ./0001-fix-darwin-build.patch

  ];

  postPatch = lib.concatStringsSep "\n" [

    # Don't reference compile time dependencies or create a build outputs cycle

    # between out and dev

      pushd ../TOOLS

      cp mpv_identify.sh umpv $out/bin/

      popd

    ''

    + lib.optionalString stdenv.hostPlatform.isLinux ''

      pushd $out/share/applications

      sed -e '/Icon=/ ! s|mpv|umpv|g; s|^Exec=.*|Exec=umpv %U|' \