8231254: (fs) Add test for macOS Catalina changes to protect system software

[Alan Bateman]

On 20/09/2019 01:01, Brian Burkhalter wrote:
> :
> I added some other tests to check a smattering of NIO API calls applied to locations in both the system (read-only) and data (read-write) volumes. These are in the checkSystemVolume() and checkDataVolume() methods.
>
> http://cr.openjdk.java.net/~bpb/8231254/webrev.01/
The test is no longer a test for FileStore so it probably should be 
moved to a new location. The file/etc directory might be okay, maybe 
name it MacVolumesTest?

In checkFirmLinks it would be better to replace L164-165 with 
Files.newBufferedReader(FIRMLINKS) and use try-with-resources to ensure 
that it closes the file.

-Alan