Throw OOME if pthread_create(3) fails.

This is how dalvik behaved, though we offer useful detail messages.

This patch also fixes a bug where we weren't actually including detail
messages in OOMEs (not just the pre-allocated one).

Change-Id: If6c8f47008a9bd058d9773f2f2e6e9a4f0d843e1
diff --git a/src/thread.h b/src/thread.h
index 310f629..c674ded 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -102,7 +102,7 @@
 
   // Creates a new native thread corresponding to the given managed peer.
   // Used to implement Thread.start.
-  static void Create(Object* peer, size_t stack_size);
+  static void CreateNativeThread(Object* peer, size_t stack_size);
 
   // Attaches the calling native thread to the runtime, returning the new native peer.
   // Used to implement JNI AttachCurrentThread and AttachCurrentThreadAsDaemon calls.