message: use libmoltenvk on ios
diff: @@ -19,9 +19,12 @@ const LIB_PATH: &'static str = "libvulkan.so.1";
  #[cfg(target_os = "android")]
  const LIB_PATH: &'static str = "libvulkan.so";
  -#[cfg(any(target_os = "macos", target_os = "ios"))]
  +#[cfg(target_os = "macos")]
  const LIB_PATH: &'static str = "libvulkan.1.dylib";
  +#[cfg(target_os = "ios")]
  +const LIB_PATH: &'static str = "libMoltenVK.dylib";
  +
  lazy_static!{
  static ref VK_LIB: Result<DynamicLibrary, String> = DynamicLibrary::open(Some(&Path::new(LIB_PATH)));
  }
  