[loader] Don't try to look for ReferenceAssemblyAttribute on dynamic …

…assemblies (Fixes #57851)

.NETFramework seems to ignore this custom attribute and allows instantiating
types from on assembly builders.

mono/metadata/assembly.c

@@ -2108,6 +2108,10 @@ has_reference_assembly_attribute_iterator (MonoImage *image, guint32 typeref_sco
 gboolean
 mono_assembly_has_reference_assembly_attribute (MonoAssembly *assembly, MonoError *error)
 {
+	g_assert (assembly && assembly->image);
+	/* .NET Framework appears to ignore the attribute on dynamic
+	 * assemblies, so don't call this function for dynamic assemblies. */
+	g_assert (!image_is_dynamic (assembly->image));
 	error_init (error);
 
 	/*
@@ -3513,8 +3517,11 @@ prevent_reference_assembly_from_running (MonoAssembly* candidate, gboolean refon
 {
 	MonoError refasm_error;
 	error_init (&refasm_error);
-	if (candidate && !refonly && mono_assembly_has_reference_assembly_attribute (candidate, &refasm_error)) {
-		candidate = NULL;
+	if (candidate && !refonly) {
+		/* .NET Framework seems to not check for ReferenceAssemblyAttribute on dynamic assemblies */
+		if (!image_is_dynamic (candidate->image) &&
+		    mono_assembly_has_reference_assembly_attribute (candidate, &refasm_error))
+			candidate = NULL;
 	}
 	mono_error_cleanup (&refasm_error);
 	return candidate;

mono/metadata/custom-attrs.c

@@ -1950,6 +1950,9 @@ mono_assembly_metadata_foreach_custom_attr (MonoAssembly *assembly, MonoAssembly
 	 */
 
 	image = assembly->image;
+	/* Dynamic images would need to go through the AssemblyBuilder's
+	 * CustomAttributeBuilder array.  Going through the tables below
+	 * definitely won't work. */
 	g_assert (!image_is_dynamic (image));
 	idx = 1; /* there is only one assembly */
 	idx <<= MONO_CUSTOM_ATTR_BITS;