ART: Clean up art_method.h

Clean up the header. Fix up other headers including the -inl file,
in an effort to prune the include graph. Fix broken transitive
includes by making includes explicit. Introduce new -inl files
for method handles and reference visiting.

Test: source build/envsetup.sh && lunch aosp_angler-userdebug && mmma art
Test: source build/envsetup.sh && lunch aosp_mips64-userdebug && mmma art
Change-Id: I8f60f1160c2a702fdf3598149dae38f6fa6bc851
diff --git a/runtime/reference_table_test.cc b/runtime/reference_table_test.cc
index 4ccfb6d..e809ecf 100644
--- a/runtime/reference_table_test.cc
+++ b/runtime/reference_table_test.cc
@@ -18,6 +18,7 @@
 
 #include "android-base/stringprintf.h"
 
+#include "art_method-inl.h"
 #include "class_linker.h"
 #include "common_runtime_test.h"
 #include "handle_scope-inl.h"