patch applied (ghc): Use timer_create() for the interval timer, if available

[Simon Marlow]

Fri Mar  2 03:31:04 PST 2007  Simon Marlow <simonmar at microsoft.com>
  * Use timer_create() for the interval timer, if available
  This lets the threaded RTS use SIGVTALRM rather than SIGALRM for its
  interval timer signal, so the threaded and non-threaded RTS are
  compatible.  It unfortunately doesn't completely fix #850/#1156, for
  that we really have to use a restartable sleep instead of usleep().
  
  Also I cleaned up the timer API a little: instead of returning an
  error value that ultimately gets ignored, we now report errors from
  system calls and exit.

    M ./configure.ac -1 +1
    M ./rts/Ticker.h -2 +2
    M ./rts/Timer.c -4 +4
    M ./rts/Timer.h -2 +2
    M ./rts/posix/Itimer.c -74 +89
    M ./rts/win32/Ticker.c -4 +7