Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Numerics/System/Numerics/HashCodeHelper.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace System.Numerics
+{
+    internal static class HashCodeHelper
+    {
+        /// <summary>
+        /// Combines two hash codes, useful for combining hash codes of individual vector elements
+        /// </summary>
+        internal static int CombineHashCodes(int h1, int h2)
+        {
+            return (((h1 << 5) + h1) ^ h2);
+        }
+    }
+}