[nicl] Converted JextractToolProviderTest as a testng test and added more tests.

[Maurizio Cimadamore]

Looks good

Thanks
Maurizio


On 23/02/18 11:50, Sundararajan Athijegannathan wrote:
> Please review: 
> http://cr.openjdk.java.net/~sundar/jextract_tool_provider_testng/webrev.00/
>
> Thanks,
> -Sundar