Fix #2740: Add nullability to HostEnvironmentInfo CpuInfo

Author: BraedenLS

src/BenchmarkDotNet/Analysers/ZeroMeasurementAnalyser.cs

@@ -19,7 +19,7 @@ private ZeroMeasurementAnalyser() { }
 
         protected override IEnumerable<Conclusion> AnalyseReport(BenchmarkReport report, Summary summary)
         {
-            var currentFrequency = summary.HostEnvironmentInfo.Cpu.Value.MaxFrequency();
+            var currentFrequency = summary.HostEnvironmentInfo.Cpu.Value?.MaxFrequency();
             if (!currentFrequency.HasValue || currentFrequency <= 0)
                 currentFrequency = FallbackCpuResolutionValue.ToFrequency();
 

src/BenchmarkDotNet/Environments/HostEnvironmentInfo.cs

@@ -38,7 +38,7 @@ public class HostEnvironmentInfo : BenchmarkEnvironmentInfo
         /// <summary>
         /// is expensive to call (1s)
         /// </summary>
-        public Lazy<CpuInfo> Cpu { get; protected set; }
+        public Lazy<CpuInfo?> Cpu { get; protected set; }
 
         public Lazy<OsInfo> Os { get; protected set; }
 
@@ -78,7 +78,7 @@ protected HostEnvironmentInfo()
             AntivirusProducts = new Lazy<ICollection<Antivirus>>(RuntimeInformation.GetAntivirusProducts);
             VirtualMachineHypervisor = new Lazy<VirtualMachineHypervisor>(RuntimeInformation.GetVirtualMachineHypervisor);
             Os = new Lazy<OsInfo>(OsDetector.GetOs);
-            Cpu = new Lazy<CpuInfo>(CpuDetector.CrossPlatform.Detect);
+            Cpu = new Lazy<CpuInfo?>(CpuDetector.CrossPlatform.Detect);
         }
 
         public new static HostEnvironmentInfo GetCurrent() => current ??= new HostEnvironmentInfo();