Prior to this commit, Elixir would never prune load
paths before compiling the current project and dependencies.
This means that if you had two independent dependencies,
`abc` and `xyz`, and `abc` was compiled before `xyz`,
`abc` would still be in the load path as `xyz` was compiled.
This commit makes it so load paths are always pruned to the
current dependencies before the project is compiled. This makes
it so unlisted Erlang apps, Elixir apps, and umbrella siblings
are no longer available. This also comes with the benefit that
we can fully remove the application tracer and compiling
dependnecies for larger applications is faster as the load paths
no longer accumulate.
Closes#12367.
Closes#12318.
José Valim
e48365242a