Fix failed uint{32,64}_t / int{32,64}_t detection on some platforms.

This commits backport python/cpython@050ba5e addressing issue 10052 [1]

[1] http://bugs.python.org/issue10052

Co-authored-by: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

Fixes #38
Merge branch '38-fix-int-uint-detection'

* 38-fix-int-uint-detection:
  Fix failed uint{32,64}_t / int{32,64}_t detection on some platforms.