remove unneeded function in ast
remove unneeded function in ast

Wilfred/racer,alkama/racer,pmarcelll/racer,asantopietro/racer,dleslie/racer,syohex/racer,andelf/racer,racer-rust/racer,marvelm/racer,phildawes/racer,bluss/racer,rranelli/racer,hotpxl/racer,drewet/racer,BonsaiDen/racer,ane/racer,syhkiller/racer,ajroetker/racer,ane/racer,MattWis/racer,ifraixedes/racer,kbknapp/racer,sthapaun/racer,birkenfeld/racer,jaxx/racer,bluss/racer,BonsaiDen/racer,drewet/racer,kbknapp/racer,asantopietro/racer,ifraixedes/racer,sthapaun/racer,syhkiller/racer,rranelli/racer,syohex/racer,ajroetker/racer,MattWis/racer,sliz1/racer