Add testcases for #2437 fixed in this PR

Author: smarter

tests/pickling/i2437a.scala

@@ -0,0 +1,5 @@
+object Test {
+  def foo(arg: Any) = arg match {
+    case bla: List[t] =>
+  }
+}

tests/pickling/i2437b.scala

@@ -0,0 +1,6 @@
+class Foo[T]
+object Test {
+  def foo[T](arg: Foo[T]) = arg match {
+    case bla: Foo[_] =>
+  }
+}