Fix comments in instr_time.h and remove an unneeded cast to int64

When Who What
2024-08-06 11:54:43 Bertrand Drouvot (bertranddrouvot.pg) Closed in commitfest 2024-09 with status: Committed
2024-08-06 11:54:43 Bertrand Drouvot (bertranddrouvot.pg) Changed committer to heikki
2024-08-06 09:22:52 Bertrand Drouvot (bertranddrouvot.pg) Changed authors to Bertrand Drouvot (bertranddrouvot.pg)
2024-08-06 09:22:52 Bertrand Drouvot (bertranddrouvot.pg) Changed targetversion to 18
2024-08-06 09:22:36 Bertrand Drouvot (bertranddrouvot.pg) Attached mail thread ZrHkv3MAQfwNSmTG@ip-10-97-1-34.eu-west-3.compute.internal
2024-08-06 09:22:36 Bertrand Drouvot (bertranddrouvot.pg) Created patch record