fix enum

Author: tarrinneal

packages/pigeon/lib/swift_generator.dart

@@ -193,8 +193,7 @@ import FlutterMacOS
           } else if (!hostDatatype.isBuiltin &&
               customEnumNames.contains(field.type.baseName)) {
             indent.writeln('var ${field.name}: $fieldType? = nil');
-            indent.write(
-                'if let ${field.name}RawValue = nullToNil(value: $listValue) as! Int? ');
+            indent.write('if let ${field.name}RawValue = $listValue as! Int? ');
             indent.addScoped('{', '}', () {
               indent.writeln(
                   '${field.name} = $fieldType(rawValue: ${field.name}RawValue)');

packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift

@@ -145,7 +145,7 @@ struct AllNullableTypes {
     let nullableMapWithAnnotations = (list[11] is NSNull) ? nullToNil(value: list[11]) as! [String?: String?]? : list[11] as! [String?: String?]? 
     let nullableMapWithObject = (list[12] is NSNull) ? nullToNil(value: list[12]) as! [String?: Any?]? : list[12] as! [String?: Any?]? 
     var aNullableEnum: AnEnum? = nil
-    if let aNullableEnumRawValue = nullToNil(value: list[13]) as! Int? {
+    if let aNullableEnumRawValue = list[13] as! Int? {
       aNullableEnum = AnEnum(rawValue: aNullableEnumRawValue)
     }
     let aNullableString = (list[14] is NSNull) ? nullToNil(value: list[14]) as! String? : list[14] as! String? 

packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift

@@ -145,7 +145,7 @@ struct AllNullableTypes {
     let nullableMapWithAnnotations = (list[11] is NSNull) ? nullToNil(value: list[11]) as! [String?: String?]? : list[11] as! [String?: String?]? 
     let nullableMapWithObject = (list[12] is NSNull) ? nullToNil(value: list[12]) as! [String?: Any?]? : list[12] as! [String?: Any?]? 
     var aNullableEnum: AnEnum? = nil
-    if let aNullableEnumRawValue = nullToNil(value: list[13]) as! Int? {
+    if let aNullableEnumRawValue = list[13] as! Int? {
       aNullableEnum = AnEnum(rawValue: aNullableEnumRawValue)
     }
     let aNullableString = (list[14] is NSNull) ? nullToNil(value: list[14]) as! String? : list[14] as! String?