[Infra] Update benchmark from 0.11.5 to 0.12.0

Author: reegeek

Build/Common.Benchmark.props

@@ -8,8 +8,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.11.5" />
-    <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.11.5" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.12.0" />
+    <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.12.0" />
   </ItemGroup>
 
   <Import Project="$(RootDir)\Build\DeleteGenerateBindingRedirects.target"/>

src/StructLinq.Benchmark/Benchmark.Main.cs

@@ -1,9 +1,14 @@
-using BenchmarkDotNet.Running;
+using System;
+using BenchmarkDotNet.Running;
 
 namespace StructLinq.Benchmark
 {
     public class Program
     {
-        public static void Main(string[] args) => BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);
+        public static void Main(string[] args)
+        {
+            BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);
+            Console.ReadLine();
+        }
     }
 }