Call ClassExt::VisitRoots

We were missing this call.

Test: ART_DEFAULT_GC_TYPE=GSS mma test-art-host
Change-Id: I559a64b04dde514888e37a86fafc260e55196f95
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index 262608d..b868563 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -85,6 +85,7 @@
 #include "linear_alloc.h"
 #include "mirror/array.h"
 #include "mirror/class-inl.h"
+#include "mirror/class_ext.h"
 #include "mirror/class_loader.h"
 #include "mirror/emulated_stack_frame.h"
 #include "mirror/field.h"
@@ -1595,6 +1596,7 @@
   mirror::MethodType::VisitRoots(visitor);
   mirror::MethodHandleImpl::VisitRoots(visitor);
   mirror::EmulatedStackFrame::VisitRoots(visitor);
+  mirror::ClassExt::VisitRoots(visitor);
   // Visit all the primitive array types classes.
   mirror::PrimitiveArray<uint8_t>::VisitRoots(visitor);   // BooleanArray
   mirror::PrimitiveArray<int8_t>::VisitRoots(visitor);    // ByteArray