stdio: call _undestroy() inside _destroy for stdout and stderr

lib/internal/bootstrap/switches/is_main_thread.js

@@ -100,6 +100,7 @@ function createWritableStdioStream(fd) {
 
 function dummyDestroy(err, cb) {
   cb(err);
+  this._undestroy();
 
   // We need to emit 'close' anyway so that the closing
   // of the stream is observable. We just make sure we

test/parallel/test-stdio-undestroy.js

@@ -0,0 +1,36 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const spawn = require('child_process').spawn;
+
+if (process.argv[2] === 'child') {
+  process.stdout.destroy();
+  process.stderr.destroy();
+  console.log('stdout');
+  process.stdout.write('rocks\n');
+  console.error('stderr');
+  setTimeout(function() {
+    process.stderr.write('rocks too\n');
+  }, 10);
+  return;
+}
+
+const proc = spawn(process.execPath, [__filename, 'child'], { stdio: 'pipe' });
+
+let stdout = '';
+proc.stdout.setEncoding('utf8');
+proc.stdout.on('data', common.mustCallAtLeast(function(chunk) {
+  stdout += chunk;
+}, 1));
+
+let stderr = '';
+proc.stderr.setEncoding('utf8');
+proc.stderr.on('data', common.mustCallAtLeast(function(chunk) {
+  stderr += chunk;
+}, 1));
+
+proc.on('exit', common.mustCall(function(exitCode) {
+  assert.strictEqual(exitCode, 0);
+  assert.strictEqual(stdout, 'stdout\nrocks\n');
+  assert.strictEqual(stderr, 'stderr\nrocks too\n');
+}));