Merge pull request #227 from shuffle2/msvc-constexpr

vs2015 supports constexpr

src/xenia/cpu/backend/x64/x64_sequence.inl

@@ -545,12 +545,7 @@ template <typename SEQ, typename T>
 struct SingleSequence : public Sequence<SingleSequence<SEQ, T>, T> {
   typedef Sequence<SingleSequence<SEQ, T>, T> BASE;
   typedef T EmitArgType;
-// TODO(benvanik): find a way to do this cross-compiler.
-#if XE_COMPILER_MSVC
-  static uint32_t head_key() { return T::key; }
-#else
   static constexpr uint32_t head_key() { return T::key; }
-#endif  // XE_COMPILER_MSVC
   static void Emit(X64Emitter& e, const typename BASE::EmitArgs& _) {
     SEQ::Emit(e, _.i1);
   }