RFE: Split gcc-libs into two packages

In mkosi, we build initrds out of distribution packages. For Arch, we currently have to manually remove many of the shared libraries from the gcc-libs package that take up a lot of space even though there are no applications that actually use them in the initrd (see https://github.com/systemd/mkosi/blob/3378be3299b7bad525ab0b321a05e9e2f91e8320/mkosi-initrd/mkosi.conf.d/10-arch.conf#L18). It would be great if gcc-libs could be split into two or more subpackages, separating the C standard library from the C++/D/Go/Fortran/... standard libraries. Then packages could just depend on the C standard library and all the other standard libraries wouldn't be installed into initrds anymore.