BUG: newlines not printed to stdout, produces different output from nim
test.nim:
```
proc foo()=
  echo "test1"
  echo ""

  echo "test2"
  echo "\n"

  echo "test3"
  var s:string = nil
  echo s


  echo "test4"
  echo "a\n"

  echo "test5"
  echo "a\nb\n"

  echo "test6"
  echo "a\n\n"

  echo "done"
foo()
```

```
 inim
INim 0.2.5
Nim Compiler Version 0.18.1 [MacOSX: amd64] at /Users/timothee/.nimble/bin/nim
>>> import bugs/t38_echo
test1
test2
test3
test4
a
test5
a
b
test6
a
done
```

```
nim c -o:app -r test.nim
test1

test2


test3

test4
a

test5
a
b

test6
a


done
```
