Fix #2198: Don't widen module singletons

Since module classes are a compiler-generated construct that's not directly
visible to programmers, it seems better not to automatically widen a module
singleton to its underlying class.

Fixes #2198.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/pos/i2198.scala b/tests/pos/i2198.scala
new file mode 100644
index 000000000..62ae7e8b5
--- /dev/null
+++ b/tests/pos/i2198.scala
@@ -0,0 +1,6 @@
+object Test {
+  val nil = scala.collection.immutable.Nil
+  def f(x: nil.type): Int = 3
+
+  f(scala.collection.immutable.Nil)
+}