Turn completions printer on as well

Author: odersky

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

@@ -27,7 +27,7 @@ object Printers {
   val incremental: Printer = noPrinter
   val config: Printer = noPrinter
   val transforms: Printer = noPrinter
-  val completions: Printer = noPrinter
+  val completions: Printer = new Printer
   val cyclicErrors: Printer = new Printer
   val pickling: Printer = noPrinter
   val inlining: Printer = noPrinter