Address reviewers comments

Author: odersky

compiler/src/dotty/tools/dotc/typer/Namer.scala

@@ -570,10 +570,10 @@ class Namer { typer: Typer =>
    *  that are already added to the symbol.
    */
   def addAnnotations(sym: Symbol, stat: MemberDef)(implicit ctx: Context) = {
-    // (1) The context in which an annotation of a top-evel class or module is evaluated
+    // (1) The context in which an annotation of a top-level class or module is evaluated
     // is the closest enclosing context which has the enclosing package as owner.
     // (2) The context in which an annotation for any other symbol is evaluated is the
-    // closest enclosing context which has the owner of the class enclpsing the symbol as owner.
+    // closest enclosing context which has the owner of the class enclosing the symbol as owner.
     // E.g in
     //
     //     package p

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1138,7 +1138,11 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
     lazy val annotCtx = {
       val c = ctx.outersIterator.dropWhile(_.owner == sym).next
       c.property(ExprOwner) match {
-        case Some(exprOwner) if c.owner.isClass => c.exprContext(mdef, exprOwner)
+        case Some(exprOwner) if c.owner.isClass =>
+          // We need to evaluate annotation arguments in an expression context, since
+          // classes defined in a such arguments should not be entered into the
+          // enclosing class.
+          c.exprContext(mdef, exprOwner)
         case None => c
       }
     }