Thank you for the review, Raymond.

Since Serhiy agrees that the _operator __func__s are unnecessary, here's a v13 that removes them.  Again, I'm not a native C speaker, so these new changes in _operator.c deserve a bit of extra scrutiny.  Everything builds and still passes the test suite, though.

Also changed in this patch, test_pow and test_inplace remove explicit testing of __func__s.  Those tests are useless, as they are merely rerunning already run tests on the same function with a different name, which is confirmed by test_dunder_is_original.  I can extend that test with an explicit list of funcs which should have a __func__ if anyone thinks it's worth it.