3912 crti needs to make sure _init and _fini are 16-byte stack aligned
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Keith M Wesolowski <wesolows@foobazco.org>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>