Pull up following revision(s) (requested by mrg in ticket #745):

sys/arch/sun3/conf/Makefile.sun3: revision 1.106
sys/arch/sun3/conf/Makefile.sun3: revision 1.107
sys/arch/sun3/conf/GENERIC3X: revision 1.131
sys/arch/sun3/include/param3.h: revision 1.57
sys/arch/sun3/conf/GENERIC: revision 1.177
sys/arch/sun3/conf/GENERIC: revision 1.178
sys/arch/sun3/include/vmparam3.h: revision 1.39

sun3:
- build libkern as an archive for non modular builds.  from maya@
- cut down GENERIC a bunch to bring below 2MB.
- reduce UBC_NWINS, MAXEXEC, and PAGER_MAP_DEFAULT_SIZE to recover
  enough lost VA to actually run basic tests.

also disable SYSCTL_INCLUDE_DESCR.

copy sun3 disables to sun3x mostly.  it has the same ufsboot 2MB limit.

Build compat code as .a if not MODULAR.

Removes some more unused functions.

(martin)