Add test

Author: TheElectronWill

tests/pos-java-interop/i7212/C.scala

@@ -0,0 +1,7 @@
+import scala.annotation._
+
+class C {
+  @varargs
+  def vargs(args: String*): Unit = println(args)
+}
+

tests/pos-java-interop/i7212/UseFromJava.java

@@ -0,0 +1,8 @@
+public class UseFromJava {
+    public void useVarargs() {
+        C c = new C();
+        c.vargs("a", "b");
+        c.vargs(new String[]{"a", "b"});
+    }
+}
+

tests/pos-java-interop/i7212/UseFromScala.scala

@@ -0,0 +1,6 @@
+class UseFromScala {
+  def useVarargs(): Unit =
+    val c = C()
+    c.vargs("a", "b")
+    c.vargs(Seq("a", "b"): _*)
+}