Add Show[Long] & Show[Unit]

[Cherry-picked 3458da7]

Author: dwijnand

compiler/src/dotty/tools/dotc/printing/Formatting.scala

@@ -125,13 +125,15 @@ object Formatting {
       given Show[Char]                                = ShowAny
       given Show[Boolean]                             = ShowAny
       given Show[Integer]                             = ShowAny
+      given Show[Long]                                = ShowAny
       given Show[String]                              = ShowAny
       given Show[Class[?]]                            = ShowAny
       given Show[Throwable]                           = ShowAny
       given Show[StringBuffer]                        = ShowAny
       given Show[CompilationUnit]                     = ShowAny
       given Show[Phases.Phase]                        = ShowAny
       given Show[TyperState]                          = ShowAny
+      given Show[Unit]                                = ShowAny
       given Show[config.ScalaVersion]                 = ShowAny
       given Show[io.AbstractFile]                     = ShowAny
       given Show[parsing.Scanners.Scanner]            = ShowAny