RFR 8153238: Improve test/tools/jlink/JLinkTest.java not to hard code the number of plugins

[Jim Laskey (Oracle)]

+1

> On Jun 24, 2016, at 1:54 PM, Sundararajan Athijegannathan <sundararajan.athijegannathan at oracle.com> wrote:
> 
> Please review http://cr.openjdk.java.net/~sundar/8153238/webrev.00/ for
> https://bugs.openjdk.java.net/browse/JDK-8153238
> 
> Thanks,
> 
> -Sundar
>