node: fix throws before timer module is loaded

An edge case could occur when the setImmediate() in _fatalException()
would fire before the timers module had been loaded globally, causing
Node to crash.

PR-URL: https://github.com/joyent/node/pull/8110
Signed-off-by: Trevor Norris <trev.norris@gmail.com>
Reviewed-by: Fedor Indutny <fedor@indutny.com>
Reviewed-by: Alexis Campailla <alexis@janeasystems.com>
Reviewed-by: Julien Gilli <julien.gilli@joyent.com>

src/node.js

@@ -255,7 +255,7 @@
 
       // if we handled an error, then make sure any ticks get processed
       } else {
-        var t = setImmediate(process._tickCallback);
+        NativeModule.require('timers').setImmediate(process._tickCallback);
       }
 
       return caught;