MFC: r260041

Record the IEEE P1282 Rock Ridge version 1.12 POSIX File Serial Number,
i. e. the POSIX:5.6.1 st_ino field, which can be used to detect hard links
in the file system. This is also the default in mkisofs(8) and according to
its man page, no system only being able to cope with Rock Ridge version 1.10
is known to exist.

PR:		185138
Submitted by:	Kurt Lidl