stage2: change logic for detecting whether the main package is inside
the std package. Previously it relied on realpath() which is not portable.
This uses resolve() which is how imports already work.
* stage2: fix cleanup bug when creating Module
* flatten lib/std/special/* to lib/*
- this was motivated by making main_pkg_is_inside_std false for
compiler_rt & friends.
* rename "mini libc" to "universal libc"
Upstream LLVM fixes#8597, no longer need `-Dskip-debug` and others.
Additionally, due to the nature of drone.io server pool, it is
beneficial to know which aarch64 CPU brand is in use.
- drop `-Dskip-debug` and others
- invoke `lscpu` prior to build
- enable more testsuite consistent with ci azure
- remove workaround for (already closed) #6830closes#8597
