Message timestamps changing

Message timestamps may no longer be unique.

In previous releases, time for messages would be shown in HHMMSS and microsecond fields. If multiple messages were sent within the same microsecond in the past, times would have been non-unique. This is not changing, microsecond granularity will continue to be available. The change will affect the 8-byte time stamp fields returned by various message operations, because bits 52-63 of the time stamp will no longer provide uniqueness (they will be 0). This change will apply to messages sent to a program message queue which make up a job log (queue space). It also applies to messages sent to non-program message queues like QSYSOPR, QHST, user profile message queues, etc. For example, the changed timestamps could be seen by serviceability tools such as trace output, the advanced analysis macro queuespace and watch for event programs called when the watch option setting is *MSGID. This change was made as a performance improvement to avoid potential scaling issues.