Created originally on Bitbucket by olliemath (Oliver Margetts)
Was already merged in Bitbucket before import, marked as merged by the import user
Improves the overall speed of adding datetimes to timedeltas as part of https://bitbucket.org/pypy/pypy/issues/2634/datetime-example-where-pypy3-is-30x-slower In conjunction with https://bitbucket.org/pypy/pypy/commits/8e5e71e this reduces the benchmark from ~390µs to ~16µs
It re-uses the add_timedelta
code from pypy2 https://bitbucket.org/pypy/pypy/src/f1ac06bafd4534859584c75c9f3e03075b6fff91/lib_pypy/datetime.py#lines-1807 which was the least intrusive change I could make with a significant improvement in speed.