This patch does:
- Cherry pick the changes for sys/queue.h from r334804.
- Merge the changes from r338102 with manually removing the changes to files not existent in stable/11, which are sys/netinet/tcp_stacks/rack.c and sys/netinet/tcp_log_buf.h, and manually resolving the conflicts in sys/netinet/tcp_var.h.
- Manually change sys/netinet/tcp_stacks/fastopen.c to make it compile with the changes in sys/netinet/tcp_var.h.
- Merge the changes from r342280.
- Merge the changes from r343439.
- Merge the changes from r344428.
It should be noted, that sys/netinet/tcp_reass.c in stable/11 is the same as in head such that future changes can still be MFCed.