Add OS validation.

Author: timcassell

src/BenchmarkDotNet/Disassemblers/DisassemblyDiagnoser.cs

@@ -109,22 +109,31 @@ public IEnumerable<ValidationError> Validate(ValidationParameters validationPara
                     yield return new ValidationError(true, "Currently NativeAOT has no DisassemblyDiagnoser support", benchmark);
                 }
 
-                if (RuntimeInformation.IsLinux() && ShouldUseClrMdDisassembler(benchmark))
+                if (ShouldUseClrMdDisassembler(benchmark))
                 {
-                    var runtime = benchmark.Job.ResolveValue(EnvironmentMode.RuntimeCharacteristic, EnvironmentResolver.Instance);
-
-                    if (runtime.RuntimeMoniker < RuntimeMoniker.NetCoreApp30)
-                    {
-                        yield return new ValidationError(true, $"{nameof(DisassemblyDiagnoser)} supports only .NET Core 3.0+", benchmark);
-                    }
-
-                    if (ptrace_scope.Value == "2")
+                    if (RuntimeInformation.IsLinux())
                     {
-                        yield return new ValidationError(false, $"ptrace_scope is set to 2, {nameof(DisassemblyDiagnoser)} is going to work only if you run as sudo");
+                        var runtime = benchmark.Job.ResolveValue(EnvironmentMode.RuntimeCharacteristic, EnvironmentResolver.Instance);
+
+                        if (runtime.RuntimeMoniker < RuntimeMoniker.NetCoreApp30)
+                        {
+                            yield return new ValidationError(true, $"{nameof(DisassemblyDiagnoser)} supports only .NET Core 3.0+", benchmark);
+                        }
+
+                        if (ptrace_scope.Value == "2")
+                        {
+                            yield return new ValidationError(false, $"ptrace_scope is set to 2, {nameof(DisassemblyDiagnoser)} is going to work only if you run as sudo");
+                        }
+                        else if (ptrace_scope.Value == "3")
+                        {
+                            yield return new ValidationError(true, $"ptrace_scope is set to 3, {nameof(DisassemblyDiagnoser)} is not going to work");
+                        }
                     }
-                    else if (ptrace_scope.Value == "3")
+                    // when we add  macOS support, RuntimeInformation.IsMacOS() needs to be added here
+                    else if (!RuntimeInformation.IsWindows())
                     {
-                        yield return new ValidationError(true, $"ptrace_scope is set to 3, {nameof(DisassemblyDiagnoser)} is not going to work");
+                        yield return new ValidationError(true, $"Only Windows and Linux are supported in DisassemblyDiagnoser without Mono. Current OS is {System.Runtime.InteropServices.RuntimeInformation.OSDescription}");
+                        yield break;
                     }
                 }
             }