Fix barrel optimization to ignore layers (#59254)
Fixes #57624. The recent issue was an unexpected side effect caused by
https://github.com/vercel/next.js/commit/305bb015060e82be3e6ae59a3d063c11a3e207f9,
which only affects specific packages like `@mui/material`.
The problem was that the entry file of `@mui/material` has `"use
client"` at top, which affects the compilation result to output
reference info only (when on the RSC layer), instead of keeping the
original export statements. And the fix here is to ignore all layer info
and React specific transforms here, as barrel optimization isn't related
to all these framework features at all. To keep all directives
unchanged, the SWC transform needs to parse and pass that info to the
Webpack loader.
This PR adds a test to ensure that `@mui/material` is working as
expected (less than 1500 modules compiled). Without this feature it'll
be ~2400 modules.
Closes NEXT-1793, closes NEXT-1762.
