Updates from tz database 2020a - following changes affects CLDR time zone data.
America/Nuuk renamted from America/Godthab. With the current CLDR policy, America/Godthab continues to be long canonical ID and America/Nuuk is added as an alias. (bcp47/timezone.xml)
Canada's Yukon advanced to UTC-7 year-round. America/Whitehorse and America/Dawson are currently mapped to metazone America_Pacific, but will be changed to America_Mountain. This change also updates Windows zone mapping. (supplemental/metaZones.xml and windowsZones.xml)
Two PRs - the former one update the CLDR data for these changes. The latter one fixed Java tooling assertion issue caused by vanguard version of tzdata files, replacing with rearguard version.