Fix #5413: Add regression tests

Author: nicolasstucki

tests/pos/i5413-a.scala

@@ -0,0 +1,7 @@
+trait Or[A]
+trait C
+
+object ImplicitChainTest {
+  def ipl[A](implicit from: A => Or[A]): C = null
+  ipl
+}

tests/pos/i5413-b.scala

@@ -0,0 +1,6 @@
+object Foo {
+  type Or[A]
+  def foo[A](from: A => Or[A]): Any = null
+  def id[A]: A => A = identity
+  foo(id)
+}