lstat error when requiring virtual modules

[craigbeck]

Latest v5.16.0 breaks with lstat error when using virtual modules:

ERROR in ../../../../derby-webpack-virtual-fs/app-views/ sync ^\.\/.*__views$
ENOENT: no such file or directory, lstat '/derby-webpack-virtual-fs'
caused by plugins in ContextModule.resolveDependencies
Error: ENOENT: no such file or directory, lstat '/derby-webpack-virtual-fs'
 @ ./node_modules/@derbyjs/derby-webpack/lib/browser.js 8:11-75

We use a plugin that writes virtual modules (using webpack-virtual-modules) code, but fails to require these modules here

This works if we pin to prior v5.15.1 version.