Make sure AnnotationTransformers run at own phase

Author: odersky

src/dotty/tools/dotc/transform/FirstTransform.scala

@@ -35,7 +35,6 @@ class FirstTransform extends MiniPhaseTransform with IdentityDenotTransformer wi
 
   override def phaseName = "firstTransform"
 
-
   def transformInfo(tp: Type, sym: Symbol)(implicit ctx: Context): Type = tp
 
   override def checkPostCondition(tree: Tree)(implicit ctx: Context): Unit = tree match {

src/dotty/tools/dotc/transform/TreeTransform.scala

@@ -177,6 +177,8 @@ object TreeTransforms {
   trait AnnotationTransformer extends MiniPhaseTransform with InfoTransformer {
 
     val annotationTransformer = mkTreeTransformer
+    override final def treeTransformPhase = this
+      // need to run at own phase because otherwise we get ahead of ourselves in transforming denotations
 
     override def transform(ref: SingleDenotation)(implicit ctx: Context): SingleDenotation = {
       val info1 = transformInfo(ref.info, ref.symbol)