bench/vectors: add instructions on how to run the C# original code with dotnet run, format vectors.cs with dotnet format

bench/vectors/README.md

@@ -1,3 +1,22 @@
+Running the C# example:
+```
+dotnet run
+```
+
+Running the V program:
+```
+v crun vectors.v
+```
+
+Running the V program, compiled with -prod:
+```
+v -prod crun vectors.v
+```
+
+Note: the `crun` will make sure that the compilation will happen just
+once at the start, and then the executable will be just reused by the
+subsequent commands with identical options.
+
 ```bash
 Benchmark 1: ./boids_test/bin/Release/net7.0/linux-x64/publish/boids_test
 Time (mean ± σ):     262.2 ms ±   5.7 ms    [User: 231.6 ms, System: 14.1 ms]

bench/vectors/vectors.cs

@@ -1,3 +1,5 @@
+using System;
+
 internal readonly struct Vector
 {
     public readonly double X;
@@ -17,9 +19,10 @@ internal readonly struct Vector
     }
 }
 
-internal static class Program
+
+class Program
 {
-    public static void Main()
+    static void Main(string[] args)
     {
         const int boidsCount = 10000;
 
@@ -187,3 +190,4 @@ internal static class Program
         Console.WriteLine(velocitySum.ToString());
     }
 }
+

bench/vectors/vectors.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+	<PublishSingleFile>true</PublishSingleFile>
+	<SelfContained>true</SelfContained>
+	
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+	<OutputType>Exe</OutputType>
+  </PropertyGroup>
+
+</Project>

bench/vectors/vectors.runtimeconfig.json

@@ -0,0 +1 @@
+{"runtimeOptions":{"framework":{"name":"Microsoft.NETCore.App","version":"7.0.10"}}}