Callers of SuspendAll should be in the kRunnable state

Change-Id: I37996164a5fd56251134683f717e6e00541cab22
diff --git a/src/signal_catcher.cc b/src/signal_catcher.cc
index 41d0fe4..4e8628d 100644
--- a/src/signal_catcher.cc
+++ b/src/signal_catcher.cc
@@ -159,6 +159,7 @@
 
   Runtime* runtime = Runtime::Current();
   runtime->AttachCurrentThread("Signal Catcher", true);
+  Thread::Current()->SetState(Thread::kRunnable);
 
   {
     MutexLock mu(signal_catcher->lock_);