firing invalid probe causes abort with nodejs v0.12

[pfmooney]

When attempting to fire a probe which has not been defined, nodejs 0.12.0 will abort with this error:

FATAL ERROR: v8::Object::GetAlignedPointerFromInternalField() Not a Smi Abort (core dumped)

I've replicated it on OSX and SmartOS:

var dtrace = require('dtrace-provider');
var provider = dtrace.createDTraceProvider('test');
provider.addProbe('present', 'int');
provider.enable();
provider.fire('present', function () {
  return 5;
});
provider.fire('absent', function () {
  return 5;
});

Node v0.10.36 does not suffer from this problem using when dtrace-provider 0.2.8 or 0.4.0.