* _Py_fopen() and _Py_stat() come from Python/import.c
 * (_Py)_wrealpath() comes from Python/sysmodule.c
 * _Py_char2wchar(), _Py_wchar2char() and _Py_wfopen() come from Modules/main.c
 * (_Py)_wstat(), (_Py)_wgetcwd(), _Py_wreadlink() come from Modules/getpath.c

Call _wfopen() on Windows, or fopen() otherwise. Return the new file object on
success, or NULL if the file cannot be open or (if PyErr_Occurred()) on unicode
error.

Use stat() or _wstat() depending on the OS.

 * Use _Py_wchar2char() in _wstat() and _Py_wfopen()
 * Document _Py_char2wchar()

at interpreter startup before importing any non-builtin modules.
Should fix #9589.

exposed in Python.h.  This function is similar to POSIX
gettimeofday(struct timeval *tp), but available on platforms without
gettimeofday().

signed/unsigned chars or on integers directly derived from those. In all
cases, it could be replaced by a simple cast to (unsigned char). Reasons
for the change:

  a) Make the comment more explicit.

  b) If char is unsigned, the cast is optimized away.

  c) If char is unsigned, gcc emits spurious "array subscript
     has type 'char'" warnings.

http://code.google.com/p/data-race-test/wiki/ThreadSanitizer is a dynamic data
race detector that runs on top of valgrind. With this patch, the binaries at
http://code.google.com/p/data-race-test/wiki/ThreadSanitizer#Binaries pass many
but not all of the Python tests. All of regrtest still passes outside of tsan.

I've implemented part of the C1x atomic types so that we can explicitly mark
variables that are used across threads, and get defined behavior as compilers
advance.

I've added tsan's client header and implementation to the codebase in
dynamic_annotations.{h,c} (docs at
http://code.google.com/p/data-race-test/wiki/DynamicAnnotations).
Unfortunately, I haven't been able to get helgrind and drd to give sensible
error messages, even when I use their client annotations, so I'm not supporting
them.