Fix a number of issues with the process handling

runtime/bin/process_linux.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/process.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
@@ skipping 88 matching lines @@
     }
     if (WIFSIGNALED(status)) {
       exit_code = WTERMSIG(status);
       negative = 1;
     }
     ProcessInfo* process = LookupProcess(pid);
     if (process != NULL) {
       int message[3] = { pid, exit_code, negative };
       intptr_t result =
           FDUtils::WriteToBlocking(process->fd(), &message, sizeof(message));
-      if (result != sizeof(message)) {
+      if (result != sizeof(message) && errno != EPIPE) {
         perror("ExitHandler notification failed");
       }
       close(process->fd());
     }
   }
 }
 
 
 int Process::Start(const char* path,
                    char* arguments[],
@@ skipping 218 matching lines @@
   if (result == -1) {
     return false;
   }
   return true;
 }
 
 
 void Process::Exit(intptr_t id) {
   RemoveProcess(id);
 }