Make concat final and inlined in IterableOps.
Make concat final and inlined in IterableOps.

scala/scala,scala/scala,martijnhoekstra/scala,scala/scala,lrytz/scala,lrytz/scala,martijnhoekstra/scala,martijnhoekstra/scala,martijnhoekstra/scala,scala/scala,lrytz/scala,lrytz/scala,lrytz/scala,scala/scala,martijnhoekstra/scala,scala/scala,lrytz/scala,martijnhoekstra/scala