JS backend: Can't return a proc that iterates over an openArray

[sls1005]

On the C backend it outputs:

> Error: 'arr' is of type <openArray[string]> which cannot be captured as it 
> would violate memory safety ... using '-d:nimNoLentIterators' helps in some 
> cases

instead of an internal compiler error. However allowing it in the JS backend 
may cause it to be inconsistent with other backends.

Anyway I think you can change it to:
    
    
    proc foo(arr: openArray[string]): proc =
      var s = @arr
      result = proc =
        for i in s:
          echo i
    
    const arr = @["qwe",]
    
    discard foo(arr)
    
    
    Run