Add punused path dependent tests

currently failing

Author: nicolasstucki

tests/pos/unused-pathdep-1.scala

@@ -0,0 +1,19 @@
+object Test {
+
+  fun1(new Bar)
+  fun2(new Bar)
+  fun3(new Bar)
+
+  def fun1[F >: Bar <: Foo](unused f: F): f.X = null.asInstanceOf[f.X]
+  def fun2[F >: Bar <: Foo](unused f: F)(unused bar: f.B): f.B = null.asInstanceOf[f.B]
+  def fun3[F >: Bar <: Foo](unused f: F)(unused b: f.B): b.X = null.asInstanceOf[b.X]
+}
+
+class Foo {
+  type X
+  type B <: Bar
+}
+
+class Bar extends Foo {
+  type X = String
+}

tests/pos/unused-pathdep-2.scala

@@ -0,0 +1,19 @@
+object Test {
+
+  type F >: Bar <: Foo
+
+  unused val f: F = new Bar
+
+  type F1 <: f.X
+  type F2[Z <: f.X]
+
+}
+
+class Foo {
+  type X
+  type B <: Bar
+}
+
+class Bar extends Foo {
+  type X = String
+}