Can't instantiate generic in some cases

[alexeypetrushin]

Wonder why `Table[string, string].init` doesn't work in default arg 
initialisation?
    
    
    import std/tables
    
    proc init*[K, V](_: type[Table[K, V]]): Table[K, V] =
      discard
    
    proc somefn(_: type[string], params = Table[string, string].init) =
      discard
    
    echo Table[string, string].init # works
    string.somefn                   # doesn't work
    
    
    Run