fixes #117

tests/compile/tcommontype.nim

@@ -0,0 +1,20 @@
+type
+  TAnimal=object {.inheritable.}
+  PAnimal=ref TAnimal
+
+  TDog=object of TAnimal
+  PDog=ref TDog
+
+  TCat=object of TAnimal
+  PCat=ref TCat
+
+  TAnimalArray=array[0..2,PAnimal]
+
+proc newDog():PDog = new(result)
+proc newCat():PCat = new(result)
+proc test(a:openarray[PAnimal])=
+  echo("dummy")
+
+#test(newDog(),newCat()) #does not work
+var myarray:TAnimalArray=[newDog(),newCat(),newDog()] #does not work
+#var myarray2:TAnimalArray=[newDog(),newDog(),newDog()] #does not work either