[CS2] CLI: Propagate SIGINT and SIGTERM signals when node is forked (#4625)

* Propagate SIGINT and SIGTERM signals when node is forked

* Use for loop for consistency

Author: Gobie

lib/coffeescript/command.js

@@ -462,6 +462,9 @@ forkNode = ->
     cwd:        process.cwd()
     env:        process.env
     stdio:      [0, 1, 2]
+  for signal in ['SIGINT', 'SIGTERM']
+    process.on signal, do (signal) ->
+      -> p.kill signal
   p.on 'exit', (code) -> process.exit code
 
 # Print the `--help` usage message and exit. Deprecated switches are not