PAX Support for minicoredumper

Upstream POSIX pax sparse-map and extended-header support that removed the legacy ustar size limit for generated core archives.

What is minicoredumper?

minicoredumper is an open-source project for creating targeted minicores instead of writing every mapped byte of a process during a core dump.

When a process receives a signal such as a segmentation fault, a core captures its memory, registers, and other state for later debugging. Not every byte is equally useful, so a minicore can retain the information needed for diagnosis while staying much smaller.

What changed?

The archive writer used the ustar format, whose field limits prevented it from representing sufficiently large core files. I added POSIX pax 1.0 sparse maps and extended headers so those files can be represented in archives that remain compatible with common GNU tar versions.

Read the upstream pull request.