Start adding more immutable collections.

Author: DarkDimius

test/dotc/scala-collections.whitelist

@@ -241,3 +241,11 @@
 #./scala-scala/src/library/scala/collection/SeqViewLike.scala
 #./scala-scala/src/library/scala/collection/TraversableView.scala
 #./scala-scala/src/library/scala/collection/TraversableViewLike.scala
+#./scala-scala/src/library/scala/collection/immutable/StreamViewLike.scala
+
+
+./scala-scala/src/library/scala/collection/immutable/HashMap.scala
+
+# seems https://github.com/lampepfl/dotty/issues/916
+#./scala-scala/src/library/scala/collection/immutable/HashSet.scala
+