Add functional tests for rejecting headers that build on invalid chains
Summary:
See title.
Co-authored-by: Jason B. Cox <contact@jasonbcox.com>
Co-authored-by: Nico Guiton <nico@bitframe.org>
Test Plan:
make check test_runner.py abc-invalid-chains
Reviewers: deadalnix, Fabien, #bitcoin_abc
Reviewed By: deadalnix, #bitcoin_abc
Subscribers: schancel
Differential Revision: https://reviews.bitcoinabc.org/D2777