Bug #1450: Illumos should be buildable with GCC4
ipf and gcc4 could get along better
There's a couple of minor nits with ipf and GCC4, that don't really warrant separating into two bugs:
- It uses
# define offsetof(t,m) (int)((&((t *)0L)->m)) and GCC4 is smart enough (now) to know that that is not necessarily representable in int (practically, it always will be, but...)
- It assigns an arbitrary 'y' to ip_hl in IP_HL_A, GCC4 wants the truncation to 4 bits to be explicit.