MKL Tests: fix TFMs and set provider hint path

MathNet.Numerics.MKL.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.28922.388
+# Visual Studio 15
+VisualStudioVersion = 15.0.28307.1082
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Common", "Common", "{5A0892FF-82CE-40FC-BCE1-73810C615F52}"
 	ProjectSection(SolutionItems) = preProject
@@ -40,6 +40,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build", "Build", "{97C9717A
 	ProjectSection(SolutionItems) = preProject
 		build\build-framework.fsx = build\build-framework.fsx
 		build.fsx = build.fsx
+		src\Directory.Build.props = src\Directory.Build.props
 		build\MathNet.Numerics.MKL.Linux-x64.nuspec = build\MathNet.Numerics.MKL.Linux-x64.nuspec
 		build\MathNet.Numerics.MKL.Linux-x86.nuspec = build\MathNet.Numerics.MKL.Linux-x86.nuspec
 		build\MathNet.Numerics.MKL.Linux.nuspec = build\MathNet.Numerics.MKL.Linux.nuspec

build.fsx

@@ -340,23 +340,23 @@ Target "Test" DoNothing
 let testMKL framework = test "src/Numerics.Tests" "Numerics.Tests.MKL.csproj" framework
 Target "MklTest" DoNothing
 Target "MklTestCore3.1" (fun _ -> testMKL "netcoreapp3.1")
-Target "MklTestNET40" (fun _ -> testMKL "net40")
+Target "MklTestNET461" (fun _ -> testMKL "net461")
 "MklWinBuild" ==> "MklTestCore3.1" ==> "MklTest"
-"MklWinBuild" =?> ("MklTestNET40", isWindows) ==> "MklTest"
+"MklWinBuild" =?> ("MklTestNET461", isWindows) ==> "MklTest"
 
 let testOpenBLAS framework = test "src/Numerics.Tests" "Numerics.Tests.OpenBLAS.csproj" framework
 Target "OpenBlasTest" DoNothing
 Target "OpenBlasTestCore3.1" (fun _ -> testOpenBLAS "netcoreapp3.1")
-Target "OpenBlasTestNET40" (fun _ -> testOpenBLAS "net40")
+Target "OpenBlasTestNET461" (fun _ -> testOpenBLAS "net461")
 "OpenBlasWinBuild" ==> "OpenBlasTestCore3.1" ==> "OpenBlasTest"
-"OpenBlasWinBuild" =?> ("OpenBlasTestNET40", isWindows) ==> "OpenBlasTest"
+"OpenBlasWinBuild" =?> ("OpenBlasTestNET461", isWindows) ==> "OpenBlasTest"
 
 let testCUDA framework = test "src/Numerics.Tests" "Numerics.Tests.CUDA.csproj" framework
 Target "CudaTest" DoNothing
 Target "CudaTestCore3.1" (fun _ -> testCUDA "netcoreapp3.1")
-Target "CudaTestNET40" (fun _ -> testCUDA "net40")
+Target "CudaTestNET461" (fun _ -> testCUDA "net461")
 "CudaWinBuild" ==> "CudaTestCore3.1" ==> "CudaTest"
-"CudaWinBuild" =?> ("CudaTestNET40", isWindows) ==> "CudaTest"
+"CudaWinBuild" =?> ("CudaTestNET461", isWindows) ==> "CudaTest"
 
 let testData framework = test "src/Data.Tests" "Data.Tests.csproj" framework
 Target "DataTest" DoNothing

src/Numerics.Tests/UseLinearAlgebraProvider.cs

@@ -28,7 +28,6 @@
 // </copyright>
 
 using System;
-
 using NUnit.Framework;
 using NUnit.Framework.Interfaces;
 
@@ -41,7 +40,9 @@ namespace MathNet.Numerics.UnitTests
         {
 
 #if NATIVE
+            string outDir = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location), @"../../../../../out/");
 #if MKL
+            Control.NativeProviderPath = System.IO.Path.Combine(outDir, @"MKL/Windows/");
             Control.UseNativeMKL();
 #elif CUDA
             Control.UseNativeCUDA();