fs: fix glob TypeError on restricted dirs

When a directory cannot be read due to permission issues, the async
version of fs.glob() returns null from readdir(), while the sync
version returns an empty array. This causes a TypeError when trying
to access the 'length' property of null.

Author: Sylphy-0xd3ac

lib/internal/fs/glob.js

@@ -143,7 +143,7 @@ class Cache {
     if (cached) {
       return cached;
     }
-    const promise = PromisePrototypeThen(readdir(path, { __proto__: null, withFileTypes: true }), null, () => null);
+    const promise = PromisePrototypeThen(readdir(path, { __proto__: null, withFileTypes: true }), null, () => []);
     this.#readdirCache.set(path, promise);
     return promise;
   }

test/parallel/test-fs-glob.mjs

@@ -518,3 +518,24 @@ describe('fsPromises glob - exclude', function() {
     });
   }
 });
+
+describe('glob - with restricted directory', function() {
+  test('*', async () => {
+    const restrictedDir = tmpdir.resolve('restricted');
+    await mkdir(restrictedDir, { recursive: true });
+    chmodSync(restrictedDir, 0o000);
+    try {
+      const results = [];
+      for await (const match of asyncGlob('*', { cwd: restrictedDir })) {
+        results.push(match);
+      }
+      assert.ok(true, 'glob completed without throwing on readdir error');
+    } finally {
+      try {
+        chmodSync(restrictedDir, 0o755);
+      } catch {
+        // ignore
+      }
+    }
+  });
+});