Each libretro profile records version_basis and core_version is read
there at its pin. snes9x states 1.63 in snes9x.h, nestopia 2.0.0, mgba
0.11.0, vice 3.10, atari800's libretro tree 7.0.0. Cores whose build
takes its version from git carry the nearest tag in describe form
(flycast v2.7-90-ge88b0ce, ppsspp, duckstation, gearcoleco), placeholders
copied from .info files (Git, SVN) are replaced by the code's statement,
and a code that states none is null with kind none.
Every cited block was read again at HEAD: no ref left to review, no
file name or hash literal added to a cited file since the pin
(--detect-new-files --watch-hashes), refs recaled with their pins.
Profiles built by a platform at a fixed commit, or whose bump would
leave prose under an older pin, stay where they were.
240 file-level entries used notes: instead of the canonical note:
field. verify.py and cross_reference.py only read note:, so these
were silently ignored.