flang-20 port is building VERY SLOWLY, "memory pressure" (Activity monitor) is very high

[Kenneth Wolcott]

Hi;

  Building flang has always been CPU+RAM intensive, but it looks like it is
thrashing now.

  Is there a way to make it go single threaded?  I have like ten "stuck"
clang processes...

  I've already tried minimize all other activity, to no avail.

Thanks,
Ken Wolcott