JDK 11 RFR of JDK-8196623: Update JavaBaseTest.java to be version agnostic

[Vicente Romero]

nit:

On 02/01/2018 07:42 PM, joe darcy wrote:
> jct.files(tb.findJavaFiles(src1))
> +            .run(Task.Expect.SUCCESS)
> +            .writeAll();

I think that you can remove the invocation to the writeAll method in 
this case as the output won't be used. Apart from that looks good

Vicente