ART: Clean up utils.h

Remove functionality provided by libbase. Move some single-use
functions to their respective users.

Test: m test-art-host
Change-Id: I75594035fa975200d638cc29bb9f31bc6e6cb29f
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 659cdda..4a8cfcb 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -125,6 +125,11 @@
   kAnalysisSuccess,
 };
 
+template <typename T>
+static inline typename std::make_unsigned<T>::type MakeUnsigned(T x) {
+  return static_cast<typename std::make_unsigned<T>::type>(x);
+}
+
 class HInstructionList : public ValueObject {
  public:
   HInstructionList() : first_instruction_(nullptr), last_instruction_(nullptr) {}