Add general multi-dimensional array test (dotnet#60749)

This is similar to MDArray2, but uses the GetLowerBound/GetUpperBound
APIs, and has a test case that uses non-zero lower bounds.
It's in the benchmarks folder as it can be used as a benchmark
to compare against MDArray2 behavior.

Author: BruceForstall

src/tests/JIT/Performance/CodeQuality/Benchstones/MDBenchI/MDGeneralArray/MDGeneralArray.cs

@@ -0,0 +1,81 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+//
+
+using System.Runtime.CompilerServices;
+
+namespace Benchstone.MDBenchI
+{
+public static class MDGeneralArray
+{
+#if DEBUG
+    public const int Iterations = 1;
+#else
+    public const int Iterations = 5000;
+#endif
+
+    static void Initialize(int[,,] s) {
+        for (int i = s.GetLowerBound(0); i <= s.GetUpperBound(0); i++) {
+            for (int j = s.GetLowerBound(1); j <= s.GetUpperBound(1); j++) {
+                for (int k = s.GetLowerBound(2); k <= s.GetUpperBound(2); k++) {
+                    s[i,j,k] = (2 * i) - (3 * j) + (5 * k);
+                }
+            }
+        }
+    }
+
+    static bool VerifyCopy(int[,,] s, int[,,] d) {
+        for (int i = s.GetLowerBound(0); i <= s.GetUpperBound(0); i++) {
+            for (int j = s.GetLowerBound(1); j <= s.GetUpperBound(1); j++) {
+                for (int k = s.GetLowerBound(2); k <= s.GetUpperBound(2); k++) {
+                    if (s[i,j,k] != d[i,j,k]) {
+                        return false;
+                    }
+                }
+            }
+        }
+
+        return true;
+    }
+    
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    static bool Bench(int loop, int[,,] s, int[,,] d) {
+
+        Initialize(s);
+
+        for (; loop != 0; loop--) {
+            for (int i = s.GetLowerBound(0); i <= s.GetUpperBound(0); i++) {
+                for (int j = s.GetLowerBound(1); j <= s.GetUpperBound(1); j++) {
+                    for (int k = s.GetLowerBound(2); k <= s.GetUpperBound(2); k++) {
+                        d[i,j,k] = s[i,j,k];
+                    }
+                }
+            }
+        }
+
+        bool result = VerifyCopy(s, d);
+
+        return result;
+    }
+
+    public static bool Test() {
+        int[,,] s = new int[10, 10, 10];
+        int[,,] d = new int[10, 10, 10];
+        return Bench(Iterations, s, d);
+    }
+
+    public static bool Test2() {
+        int[] lengths = new int[3] { 10, 10, 10 };
+        int[] lowerBounds = new int[3] { -5, 0, 5 };
+        int[,,] s = (int[,,])System.Array.CreateInstance(typeof(int), lengths, lowerBounds);
+        int[,,] d = (int[,,])System.Array.CreateInstance(typeof(int), lengths, lowerBounds);
+        return Bench(Iterations, s, d);
+    }
+
+    public static int Main() {
+        bool result = Test() && Test2();
+        return (result ? 100 : -1);
+    }
+}
+}

src/tests/JIT/Performance/CodeQuality/Benchstones/MDBenchI/MDGeneralArray/MDGeneralArray.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+  </PropertyGroup>
+  <PropertyGroup>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+  <PropertyGroup>
+    <ProjectAssetsFile>$(JitPackagesConfigFileDirectory)benchmark\obj\project.assets.json</ProjectAssetsFile>
+  </PropertyGroup>
+</Project>