Fix #1820: condition of whether generates outer

Previously, we don't generate `outer` for the anonymous class `new Inner2 {}`.
This is incorrect, as `Inner2 {}` extends `A.Inner`, which requires an outer.

trait A {
  val a = "a"
  trait Inner {
    def f = println(a)
    def h = 3
  }
}

trait B extends A {
  trait Inner2 extends Inner
  new Inner2 {}
}

1 files changed, 19 insertions, 0 deletions

diff --git a/tests/run/i1820b.scala b/tests/run/i1820b.scala
new file mode 100644
index 000000000..3452b6158
--- /dev/null
+++ b/tests/run/i1820b.scala
@@ -0,0 +1,19 @@
+trait A {
+  val a = "a"
+  trait Inner {
+    def f = println(a)
+    def h = 3
+  }
+}
+
+trait B extends A {
+  trait Inner2 extends Inner
+  def g = new Inner2 {}
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val b = new B {}
+    b.g.f
+  }
+}