Fix default parameter value.

Interesting that the tests pass even if we always assume outOfContext = true.
So this raises the question why have a flag? It's just that I am not sure the
`outOfContext` behavior is correct in all cases. So I prefer to be conservative
here.

Author: odersky

compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala

@@ -364,7 +364,7 @@ object ExplicitOuter {
      */
     def path(toCls: Symbol,
              start: Tree = This(ctx.owner.lexicallyEnclosingClass.asClass),
-             outOfContext: Boolean = true): Tree = try {
+             outOfContext: Boolean = false): Tree = try {
       def loop(tree: Tree): Tree = {
         val treeCls = tree.tpe.widen.classSymbol
         val outerAccessorCtx = ctx.withPhaseNoLater(ctx.lambdaLiftPhase) // lambdalift mangles local class names, which means we cannot reliably find outer acessors anymore