[PATCH] ntdll: Implement ProcessVmCounters for Linux.

[Alex Henrie]

So, I think Alexandre has been ignoring this patch because it only
reports correct information for the current process, even though the
Mac implementation has the same problem. I can think of a few ways to
fix that:

1. Do nothing if the handle passed to NtQueryInformationProcess is the
handle of another process.

2. Add a wineserver call such as get_process_unix_pid to get the
process's Unix PID from its handle. Modify the Mac code to use
task_for_pid and the Linux code to use /proc/%u/status.

3. Add a wineserver call such as get_process_vm_counters to get all
the information that ProcessVmCounters needs without exposing the Unix
PID. Move the Mac code into the wineserver and add the Linux code
there too.

Of those options, I think #3 makes the most sense. Ken, do you think
it will cause any problems on Mac?

-Alex