create /tmp at bootstrap, default TMPDIR used by some programs (e.g. ed)
Some small changes in preparation for a bigger change.

- typedef for ABC variables and MAX_ABC_LENGTH constant,
- cast pc->k to uint32_t in more places,
- whitespaces.
Add uao_set_pgfl to limit a uvm_aobj's pages to a specified freelist.

Brought up on tech-kern:

https://mail-index.netbsd.org/tech-kern/2014/05/20/msg017095.html
gcc-4.8.3 out.
Put missing END() markers to set ELF symbol size.
Indent.
Put missing END() markers to set ELF symbol size.
Put missing END() markers to set ELF symbol size.
Define TTY_ALLOW_PRIVATE in tty.c, tty_pty.c, and tty_conf.c.

These modules are the core of the tty code that in the long term needs
access to struct tty. (It may be that in the future this can be cut
back to just tty.c; we'll see. For now I'll settle for keeping drivers
out of struct tty.)
Use uintptr_t so this file can be compile-tested on foreign arches.
Use accessor functions for the tty's table of control characters.
(at least from outside the core tty sources)

Move some xon/xoff code from net/ppp_tty.c to kern/tty.c.
fix build for _KERNEL
- Add in_init() and move some functions, variables and sysctls into in.c
  where they belong to.  Make some functions and variables static.
- ip_input.c: reduce some #ifdefs, cleanup a little.
- Move some sysctls into ip_flow.c as they belong there.

No functional change.
Move udp6_input(), udp6_sendup(), udp6_realinput() and udp6_input_checksum()
from udp_usrreq.c to udp6_usrreq.c where they belong.  No functional change.
- Make ip_setmoptions(), ip_getmoptions() and ip_pcbopts() static.
- ip_output: eliminate 7th variadic argument; IP_RETURNMTU is flag
  always used to store MTU size into struct inpcb::inp_errormtu.
- Clean up these routines: reduce #ifdefs, variable scopes, etc.
Fix the assert in the previous commit.
PR/48831: Jörg Grundmann: Synaptics Touch pad (ClickPad) and
Klick-by-tap-gestures do not work
Define hacked version of END() in addition to ENTRY().
Put missing END() markers to set ELF symbol size.
Put missing END() markers to set ELF symbol size.