There's no need to restrict the TestRuntime.IsCoreCLR method to .NET code only.

The logic works just as well on legacy Xamarin as well.

Author: rolfbjarne

tests/common/TestRuntime.cs

@@ -1175,7 +1175,6 @@ public static bool IsOptimizeAll {
 		}
 	}
 
-#if NET
 	// There's no official API yet for distinguishing between CoreCLR and MonoVM (https://github.com/dotnet/runtime/issues/49481)
 	// (checking for the Mono.Runtime type doesn't work, because the BCL is the same, so there's never a Mono.Runtime type).
 	// However, the System.__Canon type seems to be CoreCLR-only.
@@ -1184,5 +1183,4 @@ public static bool IsCoreCLR {
 			return Type.GetType ("System.__Canon") is not null;
 		}
 	}
-#endif
 }