Incremental builds now take depfiles in account! Using a file that
contains a mapping of depfile to its cached contents, Zilch now
rebuilds less targets unnecessarily! If a build fails because an
include is added, it transparently rebuilds it with all possible header
dependencies, using the custom build scheduler built into Zilch. If an
include is removed, the target will be rebuilt with the new set of
headers the next time the CLI is invoked.
Change-Id: I6a6a6964c2fb191af4a474c45fd0f29623c588b0
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.
