Defines starting with `a' in kern

• accept1 kern/uipc_syscalls.c:168
• ACCT_ASYNC kern/subr_acct.c:55
• ACCT_RDPRI kern/subr_acct.c:53
• ACCT_RDWAIT kern/subr_acct.c:56
• ALPHA kern/tty.c:86
• ATTRP kern/kern_exec.c:185