Merge mixin with the group of miniphases following it.

Author: odersky

src/dotty/tools/dotc/Compiler.scala

@@ -54,8 +54,8 @@ class Compiler {
            new Getters,
            new ResolveSuper),
       List(new Erasure),
-      List(new Mixin),
-      List(new Memoize,
+      List(new Mixin,
+           new Memoize,
            new CapturedVars,
            new Constructors),
       List(new LambdaLift,