Replace IndexError with OverflowError in struct.pack_into()

[serhiy-storchaka]

Feature or enhancement

struct.pack_into() raises IndexError if the offset argument is too large for Py_ssize_t. It was introduced in 75c3d6f (bpo-3694), because PyLong_AsSsize_t() at that time raised SystemError for non-long. This is the only IndexError in the module -- struct.unpack_from() raises OverflowError. There were no tests for this, I only added tests just now (PR #143901).

Linked PRs

• gh-143904: Raise OverflowError instead of IndexError for too large offset in struct.pack_into() #143905