Generate valid C# for unions in templates with non-type args

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

Author: ddobrev

src/Generator/Driver.cs

@@ -221,8 +221,8 @@ public void SetupPasses(ILibrary library)
             if (Options.IsCSharpGenerator)
                 TranslationUnitPasses.AddPass(new EqualiseAccessOfOverrideAndBasePass());
 
-            TranslationUnitPasses.AddPass(new CheckIgnoredDeclsPass());
             TranslationUnitPasses.AddPass(new FlattenAnonymousTypesToFields());
+            TranslationUnitPasses.AddPass(new CheckIgnoredDeclsPass());
             TranslationUnitPasses.AddPass(new MarkUsedClassInternalsPass());
 
             if (Options.IsCSharpGenerator)

src/Generator/Passes/FlattenAnonymousTypesToFields.cs

@@ -31,8 +31,6 @@ public override bool VisitClassDecl(Class @class)
                 ReplaceField(@class, i, fieldType);
                 fieldType.Fields.Clear();
                 fieldType.ExplicitlyIgnore();
-                if (fieldType.IsUnion)
-                    @class.HasUnionFields = true;
             }
 
             if (@class.Layout == null)
@@ -50,6 +48,8 @@ public override bool VisitClassDecl(Class @class)
                 ReplaceLayoutField(@class, i, fieldType);
                 fieldType.Fields.Clear();
                 fieldType.ExplicitlyIgnore();
+                if (fieldType.IsUnion)
+                    @class.HasUnionFields = true;
             }
 
             return true;

tests/CSharp/CSharp.Tests.cs

@@ -38,6 +38,7 @@ public void TestUncompilableCode()
         new HasProtectedVirtual().Dispose();
         new Proprietor(5).Dispose();
         new HasCtorWithMappedToEnum<TestFlag>(TestFlag.Flag1).Dispose();
+        new TestAnonymousMemberNameCollision().Dispose();
         using (var testOverrideFromSecondaryBase = new TestOverrideFromSecondaryBase())
         {
             testOverrideFromSecondaryBase.function();
@@ -1749,12 +1750,6 @@ public void TestTypemapTypedefParam()
         Assert.That(CSharp.CSharp.TakeTypemapTypedefParam(false), Is.False);
     }
 
-    [Test]
-    public void TestAnonymousMemberNameCollision()
-    {
-        StringAssert.EndsWith(nameof(CSharp.TestAnonymousMemberNameCollision._0.__0), "__0");
-    }
-
     [Test]
     public void TestStringMarshall()
     {

tests/CSharp/CSharpTemplates.h

@@ -832,6 +832,12 @@ class ClassWithNonTypeTemplateArgument
 {
 public:
     ClassWithNonTypeTemplateArgument() { }
+private:
+    union
+    {
+        int i;
+        DependentValueFields<TestFlag> d;
+    };
 };
 
 class SpecializationOfClassWithNonTypeTemplateArgument : public ClassWithNonTypeTemplateArgument<0>