RFR 8148609: supportedOptions() methods return a mutable set

[vyom]

Hi All,

Please review my code changes for the below issue.
Bug: JDK-8148609 : supportedOptions() methods return a mutable set
Webrev: http://cr.openjdk.java.net/~nkumar/vyom/8148609/webrev0.0/ 
<http://cr.openjdk.java.net/%7Enkumar/vyom/8148609/webrev0.0/>

Thanks,
Vyom