test: use tmpDir instead of fixturesDir

This test was using fixturesDir to create temp files to test. This
patch replaces that with tmpDir and uses `assert` module to test.
Also, this test has been moved to `parallel`, from `sequential` mode.

PR-URL: #2583
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Rich Trott <rtrott@gmail.com>

test/parallel/test-regress-GH-3739.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+
+var dir = path.resolve(common.tmpDir);
+
+// Make sure that the tmp directory is clean
+common.refreshTmpDir();
+
+// Make a long path.
+for (var i = 0; i < 50; i++) {
+  dir = dir + '/1234567890';
+  try {
+    fs.mkdirSync(dir, '0777');
+  } catch (e) {
+    if (e.code !== 'EEXIST') {
+      throw e;
+    }
+  }
+}
+
+// Test if file exists synchronously
+assert(common.fileExists(dir), 'Directory is not accessible');
+
+// Test if file exists asynchronously
+fs.access(dir, function(err) {
+  assert(!err, 'Directory is not accessible');
+});