Address feedback.

Author: jpobst

src/Java.Interop/Java.Interop/JniRuntime.JniMarshalMemberBuilder.cs

@@ -48,8 +48,8 @@ partial void SetMarshalMemberBuilder (CreationOptions options)
 			var t   = jie.GetType ("Java.Interop.MarshalMemberBuilder");
 			if (t == null)
 				throw new InvalidOperationException ("Could not find Java.Interop.MarshalMemberBuilder from Java.Interop.Export.dll!");
-			var b   = (JniMarshalMemberBuilder?) Activator.CreateInstance (t);
-			marshalMemberBuilder    = SetRuntime (b!);
+			var b   = (JniMarshalMemberBuilder) Activator.CreateInstance (t)!;
+			marshalMemberBuilder    = SetRuntime (b);
 		}
 
 		public abstract class JniMarshalMemberBuilder : IDisposable, ISetRuntime
@@ -87,7 +87,7 @@ public  Delegate                                                CreateMarshalToM
 			{
 				if (value == null)
 					throw new ArgumentNullException (nameof (value));
-				return CreateMarshalToManagedExpression (value.GetMethodInfo ()!).Compile ();
+				return CreateMarshalToManagedExpression (value.GetMethodInfo ()).Compile ();
 			}
 
 			public  abstract    LambdaExpression                            CreateMarshalToManagedExpression (MethodInfo method);

src/Java.Interop/Java.Interop/JniRuntime.cs

@@ -290,7 +290,11 @@ static unsafe JavaVMInterface CreateInvoker (IntPtr handle)
 		public virtual void FailFast (string? message)
 		{
 			var m = typeof (Environment).GetMethod ("FailFast");
-			m?.Invoke (null, new object?[]{ message });
+
+			if (m is null)
+				Environment.Exit (1);
+
+			m.Invoke (null, new object?[]{ message });
 		}
 
 		public override string ToString ()