Fixed problem in SI-6408

Fixed problem reported in comment, where inner classes of value classe caused a compiler crash.

Author: odersky

src/compiler/scala/tools/nsc/transform/Constructors.scala

@@ -127,7 +127,8 @@ abstract class Constructors extends Transform with ast.TreeDSL {
         import CODE._
         val result = mkAssign(to, Ident(from))
 
-        if (from.name != nme.OUTER) result
+        if (from.name != nme.OUTER ||
+            from.tpe.typeSymbol.isPrimitiveValueClass) result
         else localTyper.typedPos(to.pos) {
           IF (from OBJ_EQ NULL) THEN Throw(NullPointerExceptionClass.tpe) ELSE result
         }

test/files/run/t6408.scala

@@ -0,0 +1,11 @@
+class X(val i: Int) extends AnyVal {
+  class Inner(val q: Int) {
+    def plus = i + q
+  }
+}
+
+object Test extends App {
+  val x = new X(11)
+  val i = new x.Inner(22)
+  assert(i.plus == 33)
+}