SI-7519: Additional test case covering sbt/sbt#914

Commit 32b5d50d6635320f448c92c27bc6df3acbb04451, associated with [SI-7519](https://issues.scala-lang.org/browse/SI-7519) and included in 2.11.0-M4, fixes sbt issue https://github.com/sbt/sbt/issues/914. This is a partest test covering the sbt issue.

Review by @retronym.