This makes sure that the aarch64 disk image also contains the correct
dynamic shared objects, specifically libgcc_s.so.1, as that one is a
dynamic dependency of every aarch64 executable.
To unify the x86_64 and aarch64 code paths, this commit just installs
everything from the compilers lib directory into the disk image lib
directory. This also happens for the Clang toolchain. This copies a few
extra files related to libsupc++ and libstdc++, increasing the size of
the disk image by 1.6MB. However, we were already copying libstdc++.a
manually anyway.
3a802e365c