Add PyTracebackObject struct definition (#5980)

* Add PyTracebackObject struct definition

* Add traceback module to cpython mod.rs

* news

* fmt

* Remove unnecessary whitespace in traceback.rs

Author: clin1234

newsfragments/5980.added.md

@@ -0,0 +1 @@
+Add `PyTracebackObject` struct definition

pyo3-ffi/src/cpython/mod.rs

@@ -40,6 +40,7 @@ pub(crate) mod pythonrun;
 pub(crate) mod floatobject;
 pub(crate) mod pyframe;
 pub(crate) mod pyhash;
+pub(crate) mod traceback;
 pub(crate) mod tupleobject;
 pub(crate) mod unicodeobject;
 pub(crate) mod weakrefobject;
@@ -83,6 +84,7 @@ pub use self::pylifecycle::*;
 pub use self::pymem::*;
 pub use self::pystate::*;
 pub use self::pythonrun::*;
+pub use self::traceback::*;
 pub use self::tupleobject::*;
 pub use self::unicodeobject::*;
 #[cfg(not(any(PyPy, GraalPy)))]

pyo3-ffi/src/cpython/traceback.rs

@@ -0,0 +1,12 @@
+use crate::object::PyObject;
+use crate::PyFrameObject;
+use std::ffi::c_int;
+
+#[repr(C)]
+pub struct PyTracebackObject {
+    ob_base: PyObject,
+    tb_next: *mut PyTracebackObject,
+    tb_frame: *mut PyFrameObject,
+    tb_lasti: c_int,
+    tb_lineno: c_int,
+}