Qualified name using a nested namespace

[Jiří Beneš]

Currently, one needs to write mutable::array::fill for a function fill imported from module mutable/array.
I'd like to write just array::fill instead :)

effekt/examples/pos/arrays.effekt

Line 22 in c93e5c6

 val arrWithVals: Array[String] = mutable::array::fill(4, "Hello World"); 

[Jiří Beneš]

This seems to work well as of current master: 1f0c055, closing.