Mark debugger test as failed if debug target crashes

tests/standalone/debugger/debug_lib.dart

 // Copyright (c) 2013, 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.
 
 // Library used by debugger wire protocol tests (standalone VM debugging).
 
 library DartDebugger;
 
 import "dart:async";
 import "dart:convert";
@@ skipping 642 matching lines @@
     if (socket != null) {
       socket.close().catchError((error) {
         // Print this directly in addition to adding it to the
         // error message queue, in case the error message queue
         // gets printed before this error handler is called.
         print("Error occurred while closing socket: $error");
         error("Error while closing socket: $error");
       });
     }
     var targetPid = targetProcess.pid;
-    print("Sending kill signal to process $targetPid...");
-    targetProcess.kill();
-    // If the process was already dead exitCode is already
+    if (errorsDetected || !shutdownEventSeen) {
+      print("Sending kill signal to process $targetPid...");
+      targetProcess.kill();
+    }
+    // If the process was already dead, exitCode is
     // available and we call exit() in the next event loop cycle.
     // Otherwise this will wait for the process to exit.
     targetProcess.exitCode.then((exitCode) {
       print("process $targetPid terminated with exit code $exitCode.");
+      if (exitCode != 0) {
+        error("Error: target process died with exit code $exitCode");
+      }
       if (errorsDetected) {
         print("\n===== Errors detected: =====");
         for (int i = 0; i < errors.length; i++) print(errors[i]);
         print("============================\n");
       }
       exit(errors.length);
     });
     cleanupDone = true;
   }
 }
@@ skipping 14 matching lines @@
   targetOpts.add("--debuggee");
   print('args: ${targetOpts.join(" ")}');
 
   Process.start(Platform.executable, targetOpts).then((Process process) {
     print("Debug target process started, pid ${process.pid}.");
     process.stdin.close();
     var debugger = new Debugger(process, new DebugScript(script));
   });
   return true;
 }