builds should produce "universal" binaries supporting OSes with 4k/64k page sizes

[chet]

For work related to Vera Rubin (e.g. Vera Rubin NVL72), Carbide binaries may need to run on host OSes (including Bluefield-4) that have 64k page sizes. While we could compile two binaries (that support 4k or 64k), we can also just produce "universal" binaries that support both.

It would be something like:

  rustflags = [
    ...existing...
    "link-arg=-Wl,-z,max-page-size=65536",
  ]

Now, it will produce larger binaries, but I'm not sure how much larger, and if it's significant enough that we'd care.