Native builds optimized for Cortex-A53 -O3

This project was created for package rust via attribute OBS:Maintained

PKGBUILD builds migrated from build-factory-pkgbuilds-backup.

Bootstrap toolchain layer for buildfactory (cycle breaker).

Single pacman repository that publishes binaries from bootstrap + buildfactory.

Isolated project for llvm-god-mlgo to avoid rebuild storms from buildfactory substitutions.