tcp_outflags isn't used in this source file and compilation failed with external GCC on sparc64 with:
In file included from .../rack_bbr_common.c:96:0:
.../tcp_fsm.h:88:15: error: 'tcp_outflags' defined but not used ...
static u_char tcp_outflags[TCP_NSTATES] = {
^~~~~~~~~~~~