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/array.h b/runtime/mirror/array.h
index 99565c6..11128bb 100644
--- a/runtime/mirror/array.h
+++ b/runtime/mirror/array.h
@@ -18,8 +18,8 @@
 #define ART_RUNTIME_MIRROR_ARRAY_H_
 
 #include "base/enums.h"
-#include "gc_root.h"
 #include "gc/allocator_type.h"
+#include "gc_root.h"
 #include "obj_ptr.h"
 #include "object.h"