This adds a second derivation containing a .so (stubbed) to all `.so.symbols`
edges, which represents a shared object stub. This stub is then used for all
linking afterwards, rather than the bubbled-up .so file, which was used as
workaround.
Change-Id: I6a6a69649ff04f8efe329c59e4d0172532aa7adb
Meson implements early-cutoff for shared library linking by having each .so
generate a .symbols file, and only relinking when that changes. The issue is
that this loses the direct dependency to the .so, and I'm unwilling to commit
to putting every transitive dependency in the environment's VFS. Instead,
work around it specifically for Meson.
