The early environment is typically cleared, so these new options
need the PRESERVE_EARLY_KENV kernel config(8) option. These environments
are reported as missing by kenv(1) if the option is not present in the
running kernel.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D30835
Stop calling system calls "function calls".
Use "The .Fn system call" a-la "The .Nm utility".
When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.
