handle non-auto-restart syscalls that we suspend

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on August 26, 2013 15:49:23_

xref issue #1145 For auto-restartable system calls (or at least those we can easily
identify) we will restart them for the app. For non-auto-restartable
system calls, we might interrupt the app when it is unprepared to handle it
when we send a signal for our own purposes (nudge, synchall for detach,
synchall for reset, an itimer used by a client or for pcprof). For a large
app with an itimer or which uses its own signals already, its code using
non-auto-restartable system calls already has to handle being interrupted,
and DR shouldn't have to do anything and just let the app continue in its
loop (maybe if it has statistics on the number of interruptions it might
not match native, but DR sends its own signals rarely). But some apps
might assume they don't need to loop?

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1255_