Reclassify tests

Since we don't support rewrite matches and implicit matches in their current form,
some tests need to be reclassified. They are moved to invalid. Maybe we can bring
them back later as staging tests.

Author: odersky

compiler/src/dotty/tools/dotc/config/Config.scala

@@ -161,7 +161,7 @@ object Config {
   final val showCompletions = false
 
   /** If set, enables tracing */
-  final val tracingEnabled = false
+  final val tracingEnabled = true
 
   /** Initial capacity of uniques HashMap.
    *  Note: This MUST BE a power of two to work with util.HashSet