node: add missing option to --help output

PR-URL: https://github.com/nodejs/node/pull/12763
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

src/node.cc

@@ -3623,6 +3623,7 @@ static void PrintHelp() {
          "  --no-deprecation           silence deprecation warnings\n"
          "  --trace-deprecation        show stack traces on deprecations\n"
          "  --throw-deprecation        throw an exception on deprecations\n"
+         "  --pending-deprecation      emit pending deprecation warnings\n"
          "  --no-warnings              silence all process warnings\n"
          "  --napi-modules             load N-API modules\n"
          "  --trace-warnings           show stack traces on process warnings\n"