Add a future related to using a type alias for construction of a type instance.

Though basic type aliases can be used, if the alias assigned is a result of a
function, the Chapel compiler will crash.
Whoops, need trailing line.
Merge pull request #646 from lydia-duncan/typeAliasFuture

Add a future related to using a type alias for construction of a type instance.

Though basic type aliases can be used, if the alias assigned is a result of a
function, the Chapel compiler will crash.