Add failing spec for Buffer from preload required module

spec/fixtures/module/preload-node-off-wrapper.js

@@ -0,0 +1,3 @@
+setImmediate(function () {
+  require('./preload-required-module')
+})

spec/fixtures/module/preload-required-module.js

@@ -0,0 +1,5 @@
+try {
+  console.log([typeof process, typeof setImmediate, typeof global, typeof Buffer].join(' '))
+} catch (e) {
+  console.log(e.message)
+}