[pretest]: Adapt tlmgr message strings to w64?

[Uwe Siart]

tlmgr uses "w32" in messages as a pointer to windows. Example:

,----
| C:\>tlmgr option showall
| Number of backups to keep (autobackup): 1
| Directory for backups (backupdir): tlpkg/backups
| Generate formats at installation or update (formats): 1
| Create Start menu shortcuts (w32) (desktop_integration): 1
| Change file associations (w32) (fileassocs): 0
| [...]
`----

Given that TL on windows is now 64 bit, would it make sense to also
adapt these strings to "w64"?

-- 
Uwe