The first half of this patch is a long-standing annoyance, if I attach
to debugserver with lldb while it is waiting for an lldb connection, the
syscall is interrupted and it doesn't retry, debugserver exits
immediately.
The second half is a request from another tool that is communicating
with debugserver, that we retry reads on our sockets in the same way. I
haven't dug in to the details of how they're communicating that this is
necessary, but the best I've been able to find reading the POSIX API
docs, this is fine.
rdar://117113298
87dc068280