Symlinks in node_modules cause ENOENT

I have a symlinked dependency installed with yarn (`link:../packages/foo`), foo has another symlinked dependency `bar`.

When I run `electron-rebuild`, I get:
```
✖ Rebuild Failed

An unhandled error occurred inside electron-rebuild
ENOENT: no such file or directory, stat '/Users/kaatt/Code/packages/foo/node_modules/bar'

Error: ENOENT: no such file or directory, stat '/Users/kaatt/Code/packages/foo/node_modules/bar'
```

This doesn't go away until I delete the `bar` symlink.

Start with the electron-rebuild command and the symlinked node_modules path shown in the error; trace where that path is stat'ed during rebuild. Reproduce the failure with nested Yarn-linked dependencies, then verify that rebuilding completes without requiring deletion of the bar symlink.

Written by the indexing model from the issue text.