don't leak file descriptors into runs

src/laminar.cpp

@@ -370,7 +370,7 @@ void Laminar::run() {
     sigemptyset(&mask);
     sigaddset(&mask, SIGCHLD);
     sigprocmask(SIG_BLOCK, &mask, NULL);
-    int sigchld = signalfd(-1, &mask, 0);
+    int sigchld = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
     srv->addDescriptor(sigchld, [this](const char* buf, size_t sz){
         struct signalfd_siginfo* siginfo = (struct signalfd_siginfo*) buf;
         // TODO: re-enable assertion when the cause for its triggering

src/server.cpp

@@ -407,7 +407,7 @@ void Server::start() {
     // this eventfd is just to allow us to quit the server at some point
     // in the future by adding this event to the async loop. I couldn't see
     // a simpler way...
-    efd_quit = eventfd(0,0);
+    efd_quit = eventfd(0, EFD_CLOEXEC|EFD_NONBLOCK);
     kj::Promise<void> quit = kj::evalLater([this](){
         static uint64_t _;
         auto wakeEvent = ioContext.lowLevelProvider->wrapInputFd(efd_quit);