Switching MathInternal.Min/Max to managed implementations (#208)

***NO_CI***

Author: CoryCharlton

nanoFramework.CoreLibrary/System/AssemblyInfo.cs

@@ -13,4 +13,4 @@
 [assembly: AssemblyProduct(".NET nanoFramework mscorlib")]
 [assembly: AssemblyCopyright("Copyright (c) .NET Foundation and Contributors")]
 
-[assembly: AssemblyNativeVersion("100.5.0.18")]
+[assembly: AssemblyNativeVersion("100.5.0.19")]

nanoFramework.CoreLibrary/System/Math.cs

@@ -13,10 +13,26 @@ internal static class MathInternal
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern int Abs(int val);
 
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern int Min(int val1, int val2);
+        /// <summary>
+        /// Returns the larger of two 32-bit signed integers.
+        /// </summary>
+        /// <param name="val1">The first of two 32-bit signed integers to compare. </param>
+        /// <param name="val2">The second of two 32-bit signed integers to compare. </param>
+        /// <returns>Parameter <paramref name="val1"/> or <paramref name="val2"/>, whichever is larger.</returns>
+        internal static int Max(int val1, int val2)
+        {
+            return (val1 >= val2) ? val1 : val2;
+        }
 
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern int Max(int val1, int val2);
+        /// <summary>
+        /// Returns the smaller of two 32-bit signed integers.
+        /// </summary>
+        /// <param name="val1">The first of two 32-bit signed integers to compare. </param>
+        /// <param name="val2">The second of two 32-bit signed integers to compare. </param>
+        /// <returns>Parameter <paramref name="val1"/> or <paramref name="val2"/>, whichever is smaller.</returns>
+        internal static int Min(int val1, int val2)
+        {
+            return (val2 >= val1) ? val1 : val2;
+        }
     }
 }