Most of this is just header shuffling.

Various bits of BSD and Solaris code need to know the supported number
of CPUs.

Because of how the glibc <sys/types.h> uses the glibc <sys/sysmacros.h>
we can't get at the ulong_t defintion here.

ZFS will make use of this.

Needed to emulate the Solaris kobjects later

Some cleanups in mmu.cc: Make one reference constant, and merge two
cases that did the same thing into one.

Fixed bug in munmap()ing an mprotect()ed region, which caused an
assertion failure in many SPECjvm2008 benchmarks. To check if a
page was allocated we incorrectly tested present(), which returns
false on an mprotect()ed page - and instead we should have tested
empty().

more refined implementation as a TODO. Also alias pwrite64 and
pread64 to pwrite and pread, respectively.

These functions are used in the SPECjvm2008 "derby" benchmark,
which fails without them.

Use the logger objects (through #define) instead of direct
calls to 'debug'. It decreases the default logging verbosity.
In addition, drop few debug calls w/o such #define

From info to warn

This makes porting BSD and Solaris derived code a lot easier.

Note that I had to rename __unused to __unused2 as it conflicts with
various Linux headers.

ZFS is full of dtrace tracepoints and needs this.

allows commands to specify a delimiter between tab completion
suggestions, the default is '\t' in case this function is not present
in the command interface.

Example:

[/]$ cd
dev tmp tests   usr etc console java
[/]$ cd usr/{TAB}
lib share
[/]$ cd usr/lib/{TAB}
jvm jni
[/]$ cd usr/lib/jv{TAB}m/{TAB}jre/{TAB}lib/{TAB}amd64/{ENTER}
headless    server
[/usr/lib/jvm/jre/lib/amd64]$

the tab_pretty(arg) function is called just before printing an
autocompleted suggestion, it may be used by commands to prettify their
autocompletion output, will shortly be used by the cd command

eventually causing a suspicious segfault.

Now if I can get it down to 32 bytes...

class-static variable, which is not only strange, it also means we
cannot concurrently run several programs in several threads.

Change it so run() returns the (32-bit) return value, and when execution
fails (e.g., file not found), it throws an IOException.

Note that unlike Unix where main()'s return value is limited to 8 bits,
here we decided to allow the full gamut (63-bit) of return values from
main(). main() may return -23 or 2323813 and this does not indicate
an error running it (only an exception indicates an error).

This patch also removes the arbitrary limit of 256 command line arguments
(not that anyone would need more...).