Add @Crossplatform and restrict mkfifo to unix, switch to do_run_in_out_file

Author: hoodmane

test/fs/test_nodefs_readdir.out

@@ -0,0 +1,13 @@
+listing contents of dir=/
+.
+..
+tmp
+home
+dev
+proc
+listing contents of dir=/working
+existing
+stdout
+test_nodefs_readdir.js
+test_nodefs_readdir.wasm
+success

test/test_core.py

@@ -5757,15 +5757,19 @@ def test_fs_nodefs_nofollow(self):
     self.emcc_args += ['-lnodefs.js']
     self.do_runf('fs/test_nodefs_nofollow.c', 'success')
 
+  @crossplatform
   @requires_node
   def test_fs_nodefs_readdir(self):
     # externally setup an existing folder structure: existing/a
     if self.get_setting('WASMFS'):
       self.set_setting('FORCE_FILESYSTEM')
-    os.mkfifo(os.path.join(self.working_dir, 'named_pipe'))
+    if not WINDOWS and not MACOS:
+      # Add an entry that isn't a directory, file, or link to test that we handle
+      # it correctly.
+      os.mkfifo(os.path.join(self.working_dir, 'named_pipe'))
     os.makedirs(os.path.join(self.working_dir, 'existing', 'a'))
     self.emcc_args += ['-lnodefs.js']
-    self.do_runf('fs/test_nodefs_readdir.c', 'success')
+    self.do_run_in_out_file_test('fs/test_nodefs_readdir.c')
 
   @no_windows('no symlink support on windows')
   @requires_node