Merged revisions 76740 via svnmerge from

Merged revisions 76740 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

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  r76740 | mark.dickinson | 2009-12-10 10:36:32 +0000 (Thu, 10 Dec 2009) | 8 lines

  Replace the size check for PyMem_MALLOC and PyMem_REALLOC with an almost
  equivalent[*] check that doesn't produce compiler warnings about a 'x < 0'
  check on an unsigned type.

  [*] it's equivalent for inputs of type size_t or Py_ssize_t, or any smaller
  unsigned or signed integer type.
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