Add GetTypeCode() extension methods for dnxcore50.

StackExchange.Redis/StackExchange/Redis/RedisValue.cs

 using System;
+#if DNXCORE50
+using System.Collections.Generic;
+using System.Reflection;
+#endif
 using System.Text;
 
 namespace StackExchange.Redis
@@ -606,7 +610,7 @@ object IConvertible.ToType(Type conversionType, IFormatProvider provider)
             if (conversionType== null) throw new ArgumentNullException("conversionType");
             if (conversionType== typeof(byte[])) return (byte[])this;
             if (conversionType == typeof(RedisValue)) return this;
-            switch(Type.GetTypeCode(conversionType))
+            switch(conversionType.GetTypeCode())
             {
                 case TypeCode.Boolean: return (bool)this;
                 case TypeCode.Byte: return (byte)this;
@@ -709,4 +713,48 @@ public bool TryParse(out double val)
             return TryParseDouble(blob, out val);
         }
     }
+
+#if DNXCORE50
+    internal static class ReflectionExtensions
+    {
+        internal static TypeCode GetTypeCode(this Type type)
+        {
+            if (type == null) return TypeCode.Empty;
+            TypeCode result;
+            if (typeCodeLookup.TryGetValue(type, out result)) return result;
+
+            if (type.GetTypeInfo().IsEnum)
+            {
+                type = Enum.GetUnderlyingType(type);
+                if (typeCodeLookup.TryGetValue(type, out result)) return result;
+            }
+            return TypeCode.Object;
+        }
+
+        static readonly Dictionary<Type, TypeCode> typeCodeLookup = new Dictionary<Type, TypeCode>
+        {
+            {typeof(bool), TypeCode.Boolean },
+            {typeof(byte), TypeCode.Byte },
+            {typeof(char), TypeCode.Char},
+            {typeof(DateTime), TypeCode.DateTime},
+            {typeof(decimal), TypeCode.Decimal},
+            {typeof(double), TypeCode.Double },
+            {typeof(short), TypeCode.Int16 },
+            {typeof(int), TypeCode.Int32 },
+            {typeof(long), TypeCode.Int64 },
+            {typeof(object), TypeCode.Object},
+            {typeof(sbyte), TypeCode.SByte },
+            {typeof(float), TypeCode.Single },
+            {typeof(string), TypeCode.String },
+            {typeof(ushort), TypeCode.UInt16 },
+            {typeof(uint), TypeCode.UInt32 },
+            {typeof(ulong), TypeCode.UInt64 },
+        };
+    }
+#else
+    internal static TypeCode GetTypeCode(this Type type)
+    {
+        return type.GetTypeCode();
+    }
+#endif
 }