ART: Include cleanup

Let clang-format reorder the header includes.

Derived with:

* .clang-format:
 BasedOnStyle: Google
 IncludeIsMainRegex: '(_test|-inl)?$'

* Steps:
 find . -name '*.cc' -o -name '*.h' | xargs sed -i.bak -e 's/^#include/ #include/' ; git commit -a -m 'ART: Include cleanup'
 git-clang-format -style=file HEAD^
 manual inspection
 git commit -a --amend

Test: mmma art
Change-Id: Ia963a8ce3ce5f96b5e78acd587e26908c7a70d02
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index c626897..250604b 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -20,11 +20,11 @@
 #include "base/bit_utils.h"
 #include "base/enums.h"
 #include "base/iteration_range.h"
+#include "class_flags.h"
 #include "dex_file.h"
 #include "dex_file_types.h"
-#include "class_flags.h"
-#include "gc_root.h"
 #include "gc/allocator_type.h"
+#include "gc_root.h"
 #include "imtable.h"
 #include "invoke_type.h"
 #include "modifiers.h"