Move implementations from class_root.h to -inl.h .

Make it possible to include the definition of enum ClassRoot
without pulling in a lot of other headers.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boots.
Change-Id: Ic90fdd70bfe0c5428a5c9a0d7901ea7e15b03488
diff --git a/runtime/method_handles.cc b/runtime/method_handles.cc
index 2dc9f67..78e7561 100644
--- a/runtime/method_handles.cc
+++ b/runtime/method_handles.cc
@@ -18,7 +18,7 @@
 
 #include "android-base/stringprintf.h"
 
-#include "class_root.h"
+#include "class_root-inl.h"
 #include "common_dex_operations.h"
 #include "common_throws.h"
 #include "interpreter/shadow_frame-inl.h"