Prevents accidental inheritance by child processes. If the child process is a
node process, it would try to set up a channel with the parent and consequently
never quit because the channel kept the event loop alive.
Fixes#3240.
With -e or --eval, require() can load module using relative path.
node -e 'require("./foo")'
But it can't load module from node_modules directory.
node -e 'require("foo")'
Fixes#1196.