Add test

Author: Duhemm

tests/generic-java-signatures/i3476.check

@@ -0,0 +1 @@
+OK

tests/generic-java-signatures/i3476.scala

@@ -0,0 +1,14 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    val members = classOf[Foo].getDeclaredMethods.map(_.toGenericString)
+    assert(members.forall(_ != "<java.lang.NullPointerException>"), members.mkString(", "))
+    println("OK")
+  }
+}
+class Foo {
+  def m[T](x: T): Int => T = {
+    def bar(y: Int): T = x
+    bar _
+  }
+}
+