[test] Temporary debug output for hanging tests

TBR=sigurds@chromium.org,sergiyb@chromium.org

Bug: v8:8292
Change-Id: Ic03e2884ef645231807762f6b0210e69c5f9ac74
Reviewed-on: https://chromium-review.googlesource.com/c/1282604
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56674}

tools/testrunner/testproc/sigproc.py

@@ -2,7 +2,9 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import platform
 import signal
+import subprocess
 
 from . import base
 from testrunner.local import utils
@@ -29,3 +31,8 @@ class SignalProc(base.TestProcObserver):
     print '>>> SIGTERM received, early abort...'
     self.exit_code = utils.EXIT_CODE_TERMINATED
     self.stop()
+
+    # TODO(machenbach): Remove temporary output after investigating:
+    # https://crbug.com/v8/8292
+    if platform.system() == 'Linux':
+      subprocess.call('ps -aux | grep d8', shell=True)