Issue #18552: Check return value of PyArena_AddPyObject() in obj2ast_object().
Issue #15893: frozenmain.c now handles PyMem_Malloc() failure
Issue #15893: Remove dead code
Issue #18573: Complete copy-paste from assertRaises entry to assertWarns entry.
add a test for issue #17669 (closes #18565)

Patch from Phil Connell.