RFR: 8219634: ZGC: Rename ZAddressRangeMap to ZGranuleMap

[Per Liden]

The ZAddressRangeMap currently takes an AddressRangeShift template 
argument. However, that argument is always ZPageSizeMinShift 
(ZGranuleSizeShift after JDK-8219633). Simplify ZAddressRangeMap by 
removing the AddressRangeShift template argument and rename it 
ZGranuleMap to signal that it's always dealing with granules.

Bug: https://bugs.openjdk.java.net/browse/JDK-8219634
Webrev: http://cr.openjdk.java.net/~pliden/8219634/webrev.0

/Per