Fix for SI-6034, covariant value classes.

My summary in the ticket was incorrect. The problem was that the
class type parameters were being cloned for the method and being
allowed to keep their variance. I threw in an assertion for anyone
attempting to create a method type with variant type parameters,
because hey, why should we allow such madness.

1 files changed, 1 insertions, 0 deletions

diff --git a/test/files/pos/t6034.scala b/test/files/pos/t6034.scala
new file mode 100644
index 0000000000..3558d7ff0b
--- /dev/null
+++ b/test/files/pos/t6034.scala
@@ -0,0 +1 @@
+final class OptPlus[+A](val x: A) extends AnyVal { }