Change thread.h to thread-inl.h to pick up missing Thread::Currnet for debug build in master

Change-Id: I56a4dd18ec1c212f9dbb73b14c0c0623b23c87bd
diff --git a/runtime/thread_pool.cc b/runtime/thread_pool.cc
index 674ab9d..bb6c475 100644
--- a/runtime/thread_pool.cc
+++ b/runtime/thread_pool.cc
@@ -19,7 +19,7 @@
 #include "base/casts.h"
 #include "base/stl_util.h"
 #include "runtime.h"
-#include "thread.h"
+#include "thread-inl.h"
 
 namespace art {