Fix #2871: Restore testing of JSDOMNodeJSEnv.
Fix #2871: Restore testing of JSDOMNodeJSEnv.

Tests were accidentally removed in
45203508e4406ba7d8d8aa9871536e2413027b5e.

nicolasstucki/scala-js,SebsLittleHelpers/scala-js,gzm0/scala-js,sjrd/scala-js,sjrd/scala-js,scala-js/scala-js,SebsLittleHelpers/scala-js,scala-js/scala-js,scala-js/scala-js,gzm0/scala-js,sjrd/scala-js,nicolasstucki/scala-js