nameres: Skip filenames that can't be decoded
nameres: Skip filenames that can't be decoded

This skips filenames that we can't decode while scanning for rust source
files.

Fixes #268

MattWis/racer,BonsaiDen/racer,sthapaun/racer,kbknapp/racer,BonsaiDen/racer,alkama/racer,racer-rust/racer,drewet/racer,jaxx/racer,sthapaun/racer,syhkiller/racer,MattWis/racer,hotpxl/racer,dleslie/racer,drewet/racer,syhkiller/racer,birkenfeld/racer,Wilfred/racer,phildawes/racer,sliz1/racer,pmarcelll/racer,kbknapp/racer