cli: support --experimental-top-level-await in NODE_OPTIONS

Author: dfabulich

doc/api/cli.md

@@ -1187,6 +1187,7 @@ Node.js options that are allowed are:
 * `--experimental-policy`
 * `--experimental-repl-await`
 * `--experimental-specifier-resolution`
+* `--experimental-top-level-await`
 * `--experimental-vm-modules`
 * `--experimental-wasi-unstable-preview1`
 * `--experimental-wasm-modules`

src/node_options.cc

@@ -599,7 +599,8 @@ PerIsolateOptionsParser::PerIsolateOptionsParser(
 
   AddOption("--experimental-top-level-await",
             "enable experimental support for ECMAScript Top-Level Await",
-            &PerIsolateOptions::experimental_top_level_await);
+            &PerIsolateOptions::experimental_top_level_await,
+            kAllowedInEnvironment);
   AddOption("--harmony-top-level-await", "", V8Option{});
   Implies("--experimental-top-level-await", "--harmony-top-level-await");
   Implies("--harmony-top-level-await", "--experimental-top-level-await");

test/parallel/test-cli-node-options.js

@@ -78,6 +78,10 @@ expect('--stack-trace-limit=100',
 if (!['arm', 'arm64', 's390x'].includes(process.arch))
   expect('--interpreted-frames-native-stack', 'B\n');
 
+// Workers can't eval as ES Modules. https://github.com/nodejs/node/issues/30682
+expectNoWorker('--experimental-top-level-await --input-type=module',
+               'B\n', 'console.log(await "B")');
+
 function expectNoWorker(opt, want, command, wantsError) {
   expect(opt, want, command, wantsError, false);
 }