Explicitly handle previously implicitly handled case

src/check_expr.cpp

@@ -1410,6 +1410,7 @@ gb_internal bool is_polymorphic_type_assignable(CheckerContext *c, Type *poly, T
 			    poly->Struct.soa_kind != StructSoa_None) {
 				bool ok = is_polymorphic_type_assignable(c, poly->Struct.soa_elem, source->Struct.soa_elem, true, modify_type);
 				if (ok) switch (source->Struct.soa_kind) {
+				case StructSoa_None:
 				default:
 					GB_PANIC("Unhandled SOA Kind");
 					break;