add regression test for issue #17930 (#20227)

fix was implemented in #20167, so
close the issue with a test

fixes #17930

tests/run/i17930/Foo_1.scala

@@ -0,0 +1,13 @@
+package eu.joaocosta.defaultstest
+
+object Foo {
+  def foo(x: Int, y: Int = 5): Int = x + y
+}
+
+object Bar {
+  export Foo.*
+}
+
+object App {
+  println(Bar.foo(2)) // Works
+}

tests/run/i17930/app_2.scala

@@ -0,0 +1,5 @@
+import eu.joaocosta.defaultstest._
+
+@main def Test =
+  println(Foo.foo(2)) // Works
+  println(Bar.foo(2)) // Fails with "missing argument for parameter y of method foo in object Bar: (x: Int, y: Int): Int"