module: missing scan for `node_modules`

`/usr/local/lib` has 2 sub-directories: `node` and `node_modules`.
I found `module` would not scan the npm default `globalDir`, `/usr/local/lib/node_modules`, but `/usr/local/lib/node`

Should node add `/usr/local/lib/node_modules` to its `paths`?

\cc @isaacs @indutny