Add hack to allow for self reference in type decls inside classes

trans/transpiler/phases/emit_cpp/class_.py

@@ -9,7 +9,9 @@ from transpiler.phases.emit_cpp import NodeVisitor, FunctionEmissionKind
 
 class ClassVisitor(NodeVisitor):
     def visit_ClassDef(self, node: ast.ClassDef) -> Iterable[str]:
-        yield "struct {"
+        yield f"struct {node.name}_s;"
+        yield f"extern {node.name}_s {node.name};"
+        yield f"struct {node.name}_s {{"
 
         yield "struct type {"
         inner = ClassInnerVisitor(node.inner_scope)