pkgs/top-level: fix composing "native cross" package sets

When using pkgsCross with a system that ends up the same as the
localSystem, then modifications for package sets like pksgMusl need to
be done for **both** localSystem and crossSystem. Consider the following
on x86_64-linux:

  pkgsCross.gnu64.pkgsMusl

Before this change, this would result in a musl buildPlatform, but a gnu
hostPlatform. This breaks the promise of "stacking" package sets on top
of each other.

After this change, it results in a musl buildPlatform and a musl
hostPlatform. This works better.

One could expect this to result in the same as pkgsCross.musl64, i.e. a
gnu buildPlatform and a musl hostPlatform, however I couldn't get this
to work without increasing memory usage for ci/eval by many, many GB.
This is caused by usage of pkgsi686Linux inside the main package set,
which follows the same hybrid pattern.

0 files changed, 0 insertions, 0 deletions