typeof -> decltype
typeof -> decltype

Summary:
Fix GNUism
Originally at https://github.com/facebook/fbthrift/pull/65

Test Plan: fbmake

Reviewed By: davejwatson@fb.com

Subscribers: alandau, bmatheny, mshneer

FB internal diff: D1757982

Signature: t1:1757982:1419624330:44ce04fa20831787a62ba463d6c656e98b3fbb5a

project-zerus/fbthrift,guker/fbthrift,fengshao0907/fbthrift,LinusU/fbthrift,SergeyMakarenko/fbthrift,uber/fbthrift,Orvid/fbthrift,kangkot/fbthrift,sinjar666/fbthrift,fengshao0907/fbthrift,guker/fbthrift,sinjar666/fbthrift,SergeyMakarenko/fbthrift,chjp2046/fbthrift,soumith/fbthrift,getyourguide/fbthrift,chjp2046/fbthrift,HankFaan/fbthrift,project-zerus/fbthrift,project-zerus/fbthrift,fengshao0907/fbthrift,Orvid/fbthrift,HankFaan/fbthrift,SergeyMakarenko/fbthrift,soumith/fbthrift,uber/fbthrift,maxwell-demon/fbthrift,soumith/fbthrift,soumith/fbthrift,maxwell-demon/fbthrift,SergeyMakarenko/fbthrift,LinusU/fbthrift,sinjar666/fbthrift,chjp2046/fbthrift,kangkot/fbthrift,chjp2046/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,guker/fbthrift,uber/fbthrift,LinusU/fbthrift,sinjar666/fbthrift,HankFaan/fbthrift,soumith/fbthrift,chjp2046/fbthrift,Orvid/fbthrift,uber/fbthrift,facebook/fbthrift,uber/fbthrift,facebook/fbthrift,chjp2046/fbthrift,facebook/fbthrift,chjp2046/fbthrift,guker/fbthrift,fengshao0907/fbthrift,SergeyMakarenko/fbthrift,maxwell-demon/fbthrift,getyourguide/fbthrift,project-zerus/fbthrift,kangkot/fbthrift,soumith/fbthrift,guker/fbthrift,SergeyMakarenko/fbthrift,soumith/fbthrift,maxwell-demon/fbthrift,raphaelamorim/fbthrift,fengshao0907/fbthrift,raphaelamorim/fbthrift,LinusU/fbthrift,HankFaan/fbthrift,maxwell-demon/fbthrift,kangkot/fbthrift,uber/fbthrift,kangkot/fbthrift,getyourguide/fbthrift,project-zerus/fbthrift,uber/fbthrift,chjp2046/fbthrift,fengshao0907/fbthrift,SergeyMakarenko/fbthrift,LinusU/fbthrift,kangkot/fbthrift,raphaelamorim/fbthrift,Orvid/fbthrift,SergeyMakarenko/fbthrift,kangkot/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,kangkot/fbthrift,getyourguide/fbthrift,sinjar666/fbthrift,getyourguide/fbthrift,chjp2046/fbthrift,HankFaan/fbthrift,Orvid/fbthrift,LinusU/fbthrift,guker/fbthrift,maxwell-demon/fbthrift,HankFaan/fbthrift,facebook/fbthrift,soumith/fbthrift,maxwell-demon/fbthrift,chjp2046/fbthrift,SergeyMakarenko/fbthrift,HankFaan/fbthrift,kangkot/fbthrift,HankFaan/fbthrift,getyourguide/fbthrift,facebook/fbthrift,getyourguide/fbthrift,getyourguide/fbthrift,uber/fbthrift,Orvid/fbthrift,project-zerus/fbthrift,getyourguide/fbthrift,project-zerus/fbthrift,SergeyMakarenko/fbthrift,raphaelamorim/fbthrift,Orvid/fbthrift,sinjar666/fbthrift,facebook/fbthrift,project-zerus/fbthrift,uber/fbthrift,fengshao0907/fbthrift,chjp2046/fbthrift,kangkot/fbthrift,project-zerus/fbthrift,LinusU/fbthrift,LinusU/fbthrift,project-zerus/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,HankFaan/fbthrift,uber/fbthrift,getyourguide/fbthrift,maxwell-demon/fbthrift,raphaelamorim/fbthrift,LinusU/fbthrift,chjp2046/fbthrift,fengshao0907/fbthrift,sinjar666/fbthrift,Orvid/fbthrift,fengshao0907/fbthrift,uber/fbthrift,uber/fbthrift,guker/fbthrift,sinjar666/fbthrift,LinusU/fbthrift,LinusU/fbthrift,raphaelamorim/fbthrift,facebook/fbthrift,raphaelamorim/fbthrift,guker/fbthrift,getyourguide/fbthrift,SergeyMakarenko/fbthrift,Orvid/fbthrift,guker/fbthrift,Orvid/fbthrift,sinjar666/fbthrift,raphaelamorim/fbthrift,fengshao0907/fbthrift,guker/fbthrift,project-zerus/fbthrift,maxwell-demon/fbthrift,HankFaan/fbthrift,sinjar666/fbthrift,maxwell-demon/fbthrift,getyourguide/fbthrift,project-zerus/fbthrift,Orvid/fbthrift,kangkot/fbthrift,guker/fbthrift,soumith/fbthrift,fengshao0907/fbthrift,raphaelamorim/fbthrift,facebook/fbthrift,HankFaan/fbthrift,soumith/fbthrift,soumith/fbthrift