module: exclude node:ffi from builtinModules when flag is disabled

Module.builtinModules is supposed to only list modules
that are accessible to user code.
node:ffi requires --experimental-ffi to be required,
so filter it out when the flag is not set,
mirroring the existing handling for --experimental-quic.

Refs: #63137 (comment)

Signed-off-by: Jordan Harband <ljharb@gmail.com>

Author: ljharb

lib/internal/modules/cjs/loader.js

@@ -490,6 +490,9 @@ function initializeCJS() {
   if (!getOptionValue('--experimental-quic')) {
     modules = modules.filter((i) => i !== 'node:quic');
   }
+  if (!getOptionValue('--experimental-ffi')) {
+    modules = modules.filter((i) => i !== 'node:ffi');
+  }
   Module.builtinModules = ObjectFreeze(modules);
 
   initializeCjsConditions();

test/ffi/test-ffi-module.js

@@ -31,8 +31,9 @@ test('ffi builtin is unavailable when disabled', () => {
   assert.strictEqual(signal, null);
 });
 
-test('ffi builtin is listed', () => {
+test('ffi builtin is listed when enabled', () => {
   const { stdout, stderr, status, signal } = spawnSync(process.execPath, [
+    '--experimental-ffi',
     '-p',
     'require("node:module").builtinModules.includes("node:ffi")',
   ], {
@@ -45,6 +46,21 @@ test('ffi builtin is listed', () => {
   assert.strictEqual(signal, null);
 });
 
+test('ffi builtin is not listed when disabled', () => {
+  const { stdout, stderr, status, signal } = spawnSync(process.execPath, [
+    '--no-experimental-ffi',
+    '-p',
+    'require("node:module").builtinModules.includes("node:ffi")',
+  ], {
+    encoding: 'utf8',
+  });
+
+  assert.strictEqual(stdout.trim(), 'false');
+  assert.strictEqual(stderr, '');
+  assert.strictEqual(status, 0);
+  assert.strictEqual(signal, null);
+});
+
 test('ffi can be imported from ESM', () => {
   const { stdout, stderr, status, signal } = spawnSync(process.execPath, [
     '--experimental-ffi',