Add test file

Author: odersky

tests/pos/i576.scala

@@ -0,0 +1,9 @@
+class A
+
+object Impl {
+  def foo()(implicit x: A = null): Int = 2
+  def test: Int = {
+    foo()() // ok
+    foo()   // did not work before, does now
+  }
+}