Structs starting with `i' in sys

• ioc_patch sys/cdio.h:123
• ioc_play_blocks sys/cdio.h:84
• ioc_play_track sys/cdio.h:75
• ioc_read_subchannel sys/cdio.h:91
• ioc_read_toc_entry sys/cdio.h:115
• ioc_toc_header sys/cdio.h:107
• ioc_vol sys/cdio.h:128
• iovec sys/uio.h:39
• itimerval sys/time.h:79