"gcc -Wstrict-prototypes" doesn't emit warnings about them.
Write each min/max functions on a single line so that the similarity and
triviality of the functions is more obvious.
Put the quad min/max functions in the correct place (aphabetical order).
The u_quad min/max functions are missing. Only 3 or 4 of the min/max
functions are actually used. sys/socketvar.h ``should use "lmin" but
it doesn't exist now''. lmin does exist now, but isn't used. Since we
depend on gcc for `inline', perhaps we should depend on it for __typeof
and function-expressions and use only macros min() and max() that work
for any types (I'm not sure how to handle mixed types).