[issue14126] Speed up list comprehensions by preallocating the list where possible

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka at gmail.com>:


----------
status: open -> pending
versions: +Python 3.6 -Python 3.3

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue14126>
_______________________________________