RFR 8154182: Fix java/lang/Class/getDeclaredField/FieldSetAccessibleTest.java to only use available modules

[Mandy Chung]

> On May 5, 2016, at 1:09 PM, Alexandre (Shura) Iline <alexandre.iline at oracle.com> wrote:
> 
> http://cr.openjdk.java.net/~shurailine/8154182/webrev.01/

Pushed.  I took the liberty to take out the extra-whitespace and rename the variable from x to p.

Mandy