Couple more nullability fixes.

Author: jpobst

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

@@ -155,7 +155,7 @@ static Type GetUnderlyingType (Type type, out int rank)
 			}
 
 			// `type` will NOT be an array type.
-			protected virtual string GetSimpleReference (Type type)
+			protected virtual string? GetSimpleReference (Type type)
 			{
 				return GetSimpleReferences (type).FirstOrDefault ();
 			}

tools/generator/Java.Interop.Tools.Generator.ObjectModel/Parameter.cs

@@ -250,9 +250,10 @@ public string GetGenericCall (CodeGenerationOptions opt, Dictionary<string, stri
 				return string.Format ("{0}.ToArray<{1}> ()", name, targetType.Replace ("[]",""));
 			}
 			var rgm = opt.SymbolTable.Lookup (targetType) as IRequireGenericMarshal;
-			return string.Format ("global::Java.Interop.JavaObjectExtensions.JavaCast<{0}>({1})",
+			return string.Format ("global::Java.Interop.JavaObjectExtensions.JavaCast<{0}>({1}){2}",
 					opt.GetOutputName (rgm != null ? (rgm.GetGenericJavaObjectTypeOverride () ?? targetType) : targetType),
-					name); 
+					name,
+					opt.NullForgivingOperator); 
 		}
 
 		public bool Validate (CodeGenerationOptions opt, GenericParameterDefinitionList type_params, CodeGeneratorContext context)

tools/generator/Java.Interop.Tools.Generator.ObjectModel/ReturnValue.cs

@@ -111,9 +111,10 @@ public string GetGenericReturn (CodeGenerationOptions opt, string name, Dictiona
 			if (targetType == "string")
 				return string.Format ("{0}?.ToString ()", name);
 			var rgm = opt.SymbolTable.Lookup (targetType) as IRequireGenericMarshal;
-			return string.Format ("global::Java.Interop.JavaObjectExtensions.JavaCast<{0}>({1})",
+			return string.Format ("global::Java.Interop.JavaObjectExtensions.JavaCast<{0}>({1}){2}",
 			                      rgm != null ? (rgm.GetGenericJavaObjectTypeOverride () ?? sym.FullName) : sym.FullName,
-			                      opt.GetSafeIdentifier (rgm != null ? rgm.ToInteroperableJavaObject (name) : name)); 
+			                      opt.GetSafeIdentifier (rgm != null ? rgm.ToInteroperableJavaObject (name) : name),
+			                      opt.NullForgivingOperator); 
 		}
 
 		public bool Validate (CodeGenerationOptions opt, GenericParameterDefinitionList type_params, CodeGeneratorContext context)