message: fix: allow "EsnextStage" as an alias for "ResugarStage"
  This fixes backward-incompatibility that would have required a major version bump.
diff: @@ -52,5 +52,8 @@ export function resolveOptions(options: Options): Options {
  looseJSModules: true
  };
  }
  + if (options.runToStage === 'EsnextStage') {
  + options = { ...options, runToStage: 'ResugarStage' };
  + }
  return { ...DEFAULT_OPTIONS, ...options };
  }
  