Python compat - iteritems() vs. items()

Always use `items()` and introduce extra `list(...)` call when needed.

Differential Revision: https://reviews.llvm.org/D56257

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350312 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed