Pass SIGINT signals to the spawned child process (#5861)

* Pass SIGINT signals down to the spawned child

* Kill process with correct signal

* Fix lint issues

* Fix exit for outer process

packages/babel-cli/src/babel-node.js

@@ -90,5 +90,10 @@ getV8Flags(function (err, v8Flags) {
         }
       });
     });
+
+    process.on("SIGINT", () => {
+      proc.kill("SIGINT");
+      process.exit(1);
+    });
   }
 });