Test all combinations of caller_owns_return and transfer_ownership.
Test all combinations of caller_owns_return and transfer_ownership.

ftalbrecht/pybindgen,cawka/pybindgen-old,gjcarneiro/pybindgen,ftalbrecht/pybindgen,ftalbrecht/pybindgen,ftalbrecht/pybindgen,gjcarneiro/pybindgen,cawka/pybindgen-old,gjcarneiro/pybindgen,cawka/pybindgen-old,gjcarneiro/pybindgen,cawka/pybindgen-old