Show toolchain column when multiple toolchains are used

[YegorStepanov]

The 3rd commit shows what's changed.

I removed Summary.IsMultipleRuntimes because it is actually redundant.

Now the Toolchain column will be showed only when using .WithToolchain() method.

Job.Default.WithRuntime(Net60); // toolchain not showing
Job.Default.WithRuntime(Net60).WithToolchain(Net60); // toolchain showing

I tried shortening the approval filenames, but they are still long

[adamsitnik]

I am afraid this is trickier that it looks like.

Currently when I run

cd samples\BenchmarkDotNet.Samples
dotnet run -c Release -f net6.0 --filter *IntroBasic.Sleep --join --runtimes net462 net6.0 --job dry

I get:

With your changes the toolchain column becomes visible again:

We want the toolchain column to be visible only when there are at least two benchmarks that use the same Runtime, but different Toolchain.

[YegorStepanov]

It looks that we should never display the Id column:

1. All BDN attributes (like SimpleJob) set JobId, so we can't check IdCharacterisctic.
2. We should not show Id if there is only one job, because it's already displayed under [Host].
3. When Jobs have a significant difference (e.g. different InvocationCount), then the InvocationCount column should be displayed

I think we should disallow setting JobId by user, because now it only shows up in the logs. The random Id is enough.

[YegorStepanov]

Is Latest ILCompiler the desired toolchain name? Should it be ILCompiler 7.0.0-*?

[YegorStepanov]

Ready for review.

The only problem I found is:

BenchmarkDotNet/tests/BenchmarkDotNet.Tests/Columns/JobColumnsApprovalTests.cs

Lines 92 to 97 in aa8ef43

	[FactDotNetCoreOnly("In the .Net Framework cmd job uses CsProjClassicNetToolchain while fluent and attribute jobs use RoslynToolchain by default")]
	[MethodImpl(MethodImplOptions.NoInlining)]
	public void MultipleInputColumnsDisplayTest()
	{
	var cmdConfig = ConfigParser.Parse(
	"--join --runtimes net481 net6.0 nativeaot6.0".Split(), NullLogger.Instance).config;

I didn't dare to change a default toolchain.

[YegorStepanov]

1. From Don't display Job and Toolchain column when running benchmarks for multiple runtimes #1603:

"The Job column should remain visible when the user has set the Job id in explicit way."

Done

2. Changed runtime names when called from cmd:
   net50 -> .NET 5.0
3. Changed tfm name when called from cmd:
   net50 -> net5.0 (to the correct tfm)
4. Simplified name:
   InProcessEmitToolchain -> InProcessEmit (like other toolchains)

[YegorStepanov]

Some possible improvements:

1) The [Host] section displays runtime info for each job Id.

This means that the [Host] section will only show the first job if multiple jobs have the same ID:

DefaultConfig.Instance
    .AddJob(Job.Dry)
    .AddJob(Job.Dry.WithRuntime(...)); // not displayed in the [Host] section

We can display the runtime info for each job.

2) When Id is not set, a random Id is used.

In such cases we can set the Id to be the difference between the jobs.

This is similar to how id is set using attributes. In this case, we do not need implicitId.

DefaultConfig.Instance
    .AddJob(Job.Dry)                     // id=Dry
    .AddJob(Job.Dry.WithRuntime(Net6.0)) // id=Dry-NET6.0

DefaultConfig.Instance
    .AddJob(Job.Dry.WithRuntime(Net6.0).WithInvocationCount(10)) // id=Dry-InvocationCount=10
    .AddJob(Job.Dry.WithRuntime(Net6.0)) // id=Dry

Cons:
When a new job is added, it can change another job Id (currently, the random Id is persistent)

3) Drop a point from runtime names

.NET 6.0 -> NET 6.0
.NET Framework 4.8.1 -> NET Framework 4.8.1

Look at the Host section and the Runtime column here