RFR(jdk10)(xs): 8171042: The 'REQUIRED' type in sharedPathsMiscInfo.hpp is not used and should be removed

[Jiangli Zhou]

Please help review the following small change that removes the unused ‘REQUIRED’ type in SharedPathsMiscInfo.

bug: JDK-8171042 <https://bugs.openjdk.java.net/browse/JDK-8171042>
webrev: http://cr.openjdk.java.net/~jiangli/8171042/webrev.00/ <http://cr.openjdk.java.net/~jiangli/8171042/webrev.00/>

Tested with all AppCDS tests.

Thanks,
Jiangli