You can't do that avoiding as you might like because the behaviour of
file handle numbering is defined by the standards. Hence the "f*"
versions of the calls (and of lots of other stuff)

Whether you add new syscalls or do the fd passing using flags and hide
the ugly bits in glibc is another question.

To add an example of what I mean you might end up defining "CLOCK_FD" to
indicate to use the fd in the struct, but given syscalls are trivial
codewise and would end up as

	fclock_foo(int fd, blah)
	{
		clock = fd_to_clock(fd);
		if (error)
			return error
		clock_do_foo(clock, blah);
		clock_put(clock);
	}

and

	clock_foo(int posixid, blah)
	{
		clock = posix_to_clock(posixid)
		...
		rest same
	}

as wrappers it seems hardly worth adding ugly hacks