When performing a build with NPM enabled and Python-based NPM modules

set, symlinks in .npm-workspaces would get set to the location within

the newly-installed module. That would become a dangling symlink, since

that module was installed in the isolated build environment, and if

there was an existing symlink pointing to a dev tree, it would be lost.
Now, any symlinks in .npm-workspaces that will be overridden will be

restored after a build, whether it completes successfully or errors out.

This should help to avoid confusing runtime and build issues after a new

build.

Tested a build with Review Board and watched the symlinks in the directory.

Verified that the symlinks were changed during the build and restored

after.