Turn off optimization in tests

The optimizer seems to do some optimizations regarding
simplifications of pattern matchings. This masks
errors to be reported later at erasure.

The optimizer should perform these actions only
after erasure.

Author: odersky

compiler/test/dotty/tools/vulpix/TestConfiguration.scala

@@ -53,7 +53,8 @@ object TestConfiguration {
   private val yCheckOptions = Array("-Ycheck:tailrec,resolveSuper,mixin,arrayConstructors,labelDef")
 
   val defaultUnoptimised = noCheckOptions ++ checkOptions ++ yCheckOptions ++ classPath
-  val defaultOptions = defaultUnoptimised :+ "-optimise"
+  val defaultOptimised = defaultUnoptimised :+ "-optimise"
+  val defaultOptions = defaultUnoptimised
   val allowDeepSubtypes = defaultOptions diff Array("-Yno-deep-subtypes")
   val allowDoubleBindings = defaultOptions diff Array("-Yno-double-bindings")
   val picklingOptions = defaultUnoptimised ++ Array(