Fix overriding a Java method with varargs

If A method like:
  override def foo(x: Object*)
overrides a Java method, it needs to be rewritten as:
  def foo(x: Seq[Object])
  override def foo(x: Array[Object]): Object = foo(Predef.wrapRefArray(x))

This should be handled by ElimRepeated but there were two bugs:
- `addVarArgsBridge` was called at phase `thisTransformer.next`, this is
too late to create the bridge since `T*` has already been rewritten as
`Seq[T]`
- The original method symbol needs to have the `override` flag dropped,
since it doesn't override anything.

Furthermore, RefChecks had to be moved after ElimRepeated, otherwise the
testcase would fail the overriding checks.

2 files changed, 8 insertions, 0 deletions

diff --git a/tests/pos-java-interop/varargsOverride/Base.java b/tests/pos-java-interop/varargsOverride/Base.java
new file mode 100644
index 000000000..a4607b71c
--- /dev/null
+++ b/tests/pos-java-interop/varargsOverride/Base.java
@@ -0,0 +1,5 @@
+class Base {
+  public Object foo(Object... x) {
+    return x;
+  }
+}
diff --git a/tests/pos-java-interop/varargsOverride/Sub.scala b/tests/pos-java-interop/varargsOverride/Sub.scala
new file mode 100644
index 000000000..9d3e2bf0d
--- /dev/null
+++ b/tests/pos-java-interop/varargsOverride/Sub.scala
@@ -0,0 +1,3 @@
+class Sub extends Base {
+  override def foo(x: Object*): Object = x
+}