Merge remote-tracking branch 'staging/transform/constructors' into transform/constructors

Conflicts:
	src/dotty/tools/dotc/transform/ElimByName.scala

Author: odersky

tests/neg/t7093-generics-encoding.scala

@@ -0,0 +1,34 @@
+// Encoding with type fields of the
+// variance test in pos. This time, the
+// test does not pass because of the encoding
+// This points to a difference between type members
+// and parameters which we should investigate further.
+object Test2 {
+
+  trait A {
+    type X
+    protected[this] def f(x: X): X = x
+  }
+
+  trait B extends A {
+    type X <: B
+    def kaboom = f(new B {})
+  }
+
+// protected[this] disables variance checking
+// of the signature of `f`.
+//
+// C's parent list unifies A[B] with A[C]
+//
+// The protected[this] loophole is widely used
+// in the collections, every newBuilder method
+// would fail variance checking otherwise.
+  class C extends B with A {
+    type X <: C
+    override protected[this] def f(c: C) = c
+  }
+
+// java.lang.ClassCastException: B$$anon$1 cannot be cast to C
+//  at C.f(<console>:15)
+  new C().kaboom
+}

tests/neg/t7093.scala

@@ -0,0 +1,13 @@
+
+object Test2 {
+
+  trait A {
+    type X
+    protected[this] def f(x: X): X = x
+  }
+
+  trait B extends A {
+    type X <: B
+    def kaboom = f(new B {})
+  }
+}

tests/pending/pos/test.scala

@@ -0,0 +1,12 @@
+object Test {
+
+  object returns {
+
+    def foo(x: Int): Int = {
+      return 3
+    }
+  }
+
+}
+
+

tests/pos/test.scala

@@ -0,0 +1,5 @@
+object Test {
+
+  def foo(x: Int): Int = return 3
+
+}

tests/pos/trees.scala

@@ -0,0 +1,5 @@
+class Tree[T]
+
+class Empty[T] extends Tree[Nothing]
+class Node[T](elem: T, l: Tree[T], r: Tree[T])
+