Infer namedtuple's arguments

[pylint-bot]

Originally reported by: Claudiu Popa (BitBucket: PCManticore, GitHub: @PCManticore)

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We could probably understand this:

#!python

from collections import namedtuple
a = namedtuple('a', 'a b c')
f = a(1, 2, 3)
f. b.x # int has no member 'x'

We currently don't because the attributes used are EmptyNodes and they don't reflect the proper values passed at initialisation.

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• Bitbucket: https://bitbucket.org/logilab/astroid/issue/109