[11] RFR JDK-8196310: jlink --suggest-providers fails with missing resource if --output specified

[mandy chung]

Webrev: 
http://cr.openjdk.java.net/~mchung/jdk11/webrevs/8196310/webrev.00/ 
Improve the error message when invalid argument is specified to 
--suggest-providers option. $ jlink --add-modules java.base 
--suggest-providers java.security.Provider --output myimage Error: 
--suggest-providers does not accept "--output myimage" argument Mandy