move ARM64 JIT backend here

src/dolphin/MathUtil.cpp

@@ -0,0 +1,13 @@
+// Copyright 2008 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "MathUtil.h"
+
+#include <numeric>
+
+// Calculate sum of a float list
+float MathFloatVectorSum(const std::vector<float>& Vec)
+{
+  return std::accumulate(Vec.begin(), Vec.end(), 0.0f);
+}