ART: Some header cleaning around bit-utils

Try to remove dependencies where they are not necessary.

Change-Id: I5ff35cb17aea369bed3725b1610b50d7eb05b81e
diff --git a/disassembler/disassembler_arm.cc b/disassembler/disassembler_arm.cc
index 03fac18..5e2cf6b 100644
--- a/disassembler/disassembler_arm.cc
+++ b/disassembler/disassembler_arm.cc
@@ -22,6 +22,7 @@
 #include <sstream>
 
 #include "arch/arm/registers_arm.h"
+#include "base/bit_utils.h"
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "thread.h"