Portable Python script across Python version

Using from __future__ import print_function it is possible to have a compatible behavior of `print(...)` across Python version.

Differential Revision: https://reviews.llvm.org/D55213

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@349454 91177308-0d34-0410-b5e6-96231b3b80d8
21 files changed