Issue #12911: Fix memory consumption when calculating the repr() of huge tuples or...

This introduces a small private API for this common pattern.
The issue has been discovered thanks to Martin's huge-mem buildbot.

diff --cc Include/Python.h
Simple merge

diff --cc Makefile.pre.in
index 52743e434ab3aaf905f67b9d01a4bf1fe585d8e0,cde3af0c420e653196961d20abf13536ebb4745a..51da7a55af65e959e8b36a8650af114446afd899
--- 1/Makefile.pre.in
--- 2/Makefile.pre.in
+++ b/Makefile.pre.in
@@@ -659,8 -662,10 +660,9 @@@ $(srcdir)/Objects/typeslots.inc: $(srcd
  # Header files
  
  PYTHON_HEADERS= \
 -              Include/Python-ast.h \
                Include/Python.h \
                Include/abstract.h \
+               Include/accu.h \
                Include/asdl.h \
                Include/ast.h \
                  Include/bltinmodule.h \

diff --cc Misc/NEWS
index 9564891fc13ea0feb89aaad7321895fa309f7b85,67227b118c27b5e6f589e92ccb3a5b1a59c7c63a..af31f9f67dd07215b8d4d2e9feff6e179b1f3548
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,13 -10,9 +10,16 @@@ What's New in Python 3.3 Alpha 1
  Core and Builtins
  -----------------
  
+ - Issue #12911: Fix memory consumption when calculating the repr() of huge
+   tuples or lists.
+ 
 +- PEP 393: flexible string representation. Thanks to Torsten Becker for the
 +  initial implementation, and Victor Stinner for various bug fixes.
 +
 +- Issue #13012: The 'keepends' parameter to str.splitlines may now be passed
 +  as a keyword argument:  "my_string.splitlines(keepends=True)".  The same
 +  change also applies to bytes.splitlines and bytearray.splitlines.
 +
  - Issue #7732: Don't open a directory as a file anymore while importing a
    module. Ignore the direcotry if its name matchs the module name (e.g.
    "__init__.py") and raise a ImportError instead.

diff --cc Objects/listobject.c
Simple merge

diff --cc Objects/tupleobject.c
Simple merge

diff --cc PC/VC6/pythoncore.dsp
Simple merge

diff --cc PC/VS7.1/pythoncore.vcproj
Simple merge

diff --cc PCbuild/pythoncore.vcproj
Simple merge