Full-source bootstrap of gcc16 for x86_64: the only binary contributing code is the hex0 seed (bootstrap-tcc), followed by regular packages tcc, gcc40, gcc48, gcc7, gcc16, each built only by its predecessor, without PGO and reproducibly.

Repositories:
- chain: the bootstrap chain (%bootstrap_chain 1); build roots contain no distro compiler.
- openSUSE_Slowroll: baseline builds of the same specs with the distro compiler, for comparison (diverse double compile of gcc16).