RFR: 8246431: java/net/httpclient/PathSubscriber tests fail due to missing FilePermission

[Julia Boes]

Hi,

The tests in java/net/httpclient/PathSubscriber don't grant certain file 
permissions to test library classes. The tests succeed by chance when 
the compiled library classes are placed under ${test.classes}, but 
occasionally they fail, depending on which test target compiles the 
library first. This fix adds a FilePermission to the test/lib code base 
to cover all cases.

Bug: https://bugs.openjdk.java.net/browse/JDK-8246431

Webrev: http://cr.openjdk.java.net/~jboes/webrevs/8246431/webrev.00/

Cheers,

Julia