[tex-k] test failure with pmpostdir/pmpsamp and pmpostdir/upmpsamp.test

[Karl Berry]

    jfbu> Today I build from source on mac os 10.3.6 (high sierra) ...

    hy>
    $ mpost -ini -tex=etex plain.mp
    This is MetaPost, version 2.02 (TeX Live 2023/dev) (kpathsea version 6.3.5/dev)
    (/usr/local/texlive/2022/texmf-dist/metapost/base/plain.mp
    Segmentation fault: 11

That is sad. It doesn't happen for me on GNU/Linux.

Akira already fixed it (Luigi: in TL r63415, please import
upstream). I'm somewhat surprised that
= vs. == typo doesn't cause problems on all systems. Maybe we need to
rebuild mpost. Hmm. Luigi, wdyt?

By the way, in general, please report mpost bugs to
mp-implementors at tug.org (see end of --help :).  Luigi is not on
tex-k. Cc'd here ... -k