feat(unstable): Add file locking APIs (#11746)

This commit adds following unstable APIs:
- Deno.flock()
- Deno.flockSync()
- Deno.funlock()
- Deno.funlockSync()

runtime/js/30_fs.js

@@ -385,6 +385,22 @@
     await core.opAsync("op_fsync_async", rid);
   }
 
+  function flockSync(rid, exclusive) {
+    core.opSync("op_flock_sync", rid, exclusive === true);
+  }
+
+  async function flock(rid, exclusive) {
+    await core.opAsync("op_flock_async", rid, exclusive === true);
+  }
+
+  function funlockSync(rid) {
+    core.opSync("op_funlock_sync", rid);
+  }
+
+  async function funlock(rid) {
+    await core.opAsync("op_funlock_async", rid);
+  }
+
   window.__bootstrap.fs = {
     cwd,
     chdir,
@@ -433,5 +449,9 @@
     fdatasyncSync,
     fsync,
     fsyncSync,
+    flock,
+    flockSync,
+    funlock,
+    funlockSync,
   };
 })(this);

runtime/js/90_deno_ns.js

@@ -136,5 +136,9 @@
     createHttpClient: __bootstrap.fetch.createHttpClient,
     http: __bootstrap.http,
     dlopen: __bootstrap.ffi.dlopen,
+    flock: __bootstrap.fs.flock,
+    flockSync: __bootstrap.fs.flockSync,
+    funlock: __bootstrap.fs.funlock,
+    funlockSync: __bootstrap.fs.funlockSync,
   };
 })(this);