RFR(XS): 8207007: Add missing license header to zHash.inline.hpp

[Mikael Vidstedt]

Please review this small change which adds the missing license header to one of the ZGC files:

Bug: https://bugs.openjdk.java.net/browse/JDK-8207007
Webrev: http://cr.openjdk.java.net/~mikael/webrevs/8207007/webrev.00/open/webrev/ <http://cr.openjdk.java.net/~mikael/webrevs/8207007/webrev.00/open/webrev/>

Cheers,
Mikael