Fix crash when using HardwareCounter.NotSet (#2124)

* Skip HardwareCounter.NotSet

* Add test

Author: YegorStepanov

src/BenchmarkDotNet/Configs/ImmutableConfigBuilder.cs

@@ -40,7 +40,7 @@ public static ImmutableConfig Create(IConfig source)
             var uniqueLoggers = source.GetLoggers().ToImmutableHashSet();
             var configAnalyse = new List<Conclusion>();
 
-            var uniqueHardwareCounters = source.GetHardwareCounters().ToImmutableHashSet();
+            var uniqueHardwareCounters = source.GetHardwareCounters().Where(counter => counter != HardwareCounter.NotSet).ToImmutableHashSet();
             var uniqueDiagnosers = GetDiagnosers(source.GetDiagnosers(), uniqueHardwareCounters);
             var uniqueExporters = GetExporters(source.GetExporters(), uniqueDiagnosers, configAnalyse);
             var uniqueAnalyzers = GetAnalysers(source.GetAnalysers(), uniqueDiagnosers);

tests/BenchmarkDotNet.Tests/Configs/ImmutableConfigTests.cs

@@ -71,6 +71,20 @@ public void DuplicateHardwareCountersAreExcluded()
             Assert.Equal(HardwareCounter.CacheMisses, final.GetHardwareCounters().Single());
         }
 
+        [Fact]
+        public void NoSetHardwareCounterIsExcluded()
+        {
+            var mutable = ManualConfig.CreateEmpty();
+
+            mutable.AddHardwareCounters(HardwareCounter.NotSet);
+            mutable.AddHardwareCounters(HardwareCounter.CacheMisses);
+
+            var final = ImmutableConfigBuilder.Create(mutable);
+
+            Assert.Single(final.GetHardwareCounters());
+            Assert.Equal(HardwareCounter.CacheMisses, final.GetHardwareCounters().Single());
+        }
+
         [FactClassicDotNetOnly(skipReason: "We have hardware counters diagnosers only for Windows. This test is disabled for .NET Core because NativeAOT compiler goes crazy when some dependency has reference to TraceEvent...")]
         public void WhenUserDefinesHardwareCountersWeChooseTheRightDiagnoser()
         {