Issue #18552: Check return value of PyArena_AddPyObject() in obj2ast_object().

diff --cc Misc/NEWS
index 321ab6e578df1ce314501f2b0fc5bdfe7673946a,ff6fe06db7b4323a7983cddfe68af217350b7188..80bf9fd0f75f4f646f81862771ad955dfa0cf5bb
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,12 -12,11 +10,15 @@@ What's New in Python 3.4.0 Alpha 1
  Core and Builtins
  -----------------
  
+ - Issue #18552: Check return value of PyArena_AddPyObject() in
+   obj2ast_object().
+ 
  - Issue #18560: Fix potential NULL pointer dereference in sum().
  
 +- Issue #18520: Add a new PyStructSequence_InitType2() function, same than
 +  PyStructSequence_InitType() except that it has a return value (0 on success,
 +  -1 on error).
 +
  - Issue #15905: Fix theoretical buffer overflow in handling of sys.argv[0],
    prefix and exec_prefix if the operation system does not obey MAXPATHLEN.
  

diff --cc Parser/asdl_c.py
Simple merge

diff --cc Python/Python-ast.c
Simple merge