Quick-fix #2704, to get Olaf unblocked.

This is not a proper fix, it just fixes the crash.
We need to figure out why this happens and handle it correctly.

Author: DarkDimius

compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala

@@ -224,7 +224,8 @@ class DottyBackendInterface(outputDirectory: AbstractFile, val superCallsMap: Ma
   def shouldEmitAnnotation(annot: Annotation): Boolean = {
     annot.symbol.isJavaDefined &&
       retentionPolicyOf(annot) != AnnotationRetentionSourceAttr &&
-      annot.args.isEmpty
+      annot.args.isEmpty &&
+      !annot.tree.isInstanceOf[Block] // unblocking Olaf, needs a proper fix
   }
 
   private def retentionPolicyOf(annot: Annotation): Symbol =
@@ -527,6 +528,7 @@ class DottyBackendInterface(outputDirectory: AbstractFile, val superCallsMap: Ma
 
   def assocsFromApply(tree: Tree) = {
     tree match {
+      case Block(_, expr) => assocsFromApply(expr)
       case Apply(fun, args) =>
         fun.tpe.widen match {
           case MethodType(names) =>