fix crash in R tokenizer when byte 0xFFFF is present in file
fix crash in R tokenizer when byte 0xFFFF is present in file

jrnold/rstudio,brsimioni/rstudio,pssguy/rstudio,brsimioni/rstudio,vbelakov/rstudio,sfloresm/rstudio,sfloresm/rstudio,john-r-mcpherson/rstudio,thklaus/rstudio,jrnold/rstudio,edrogers/rstudio,brsimioni/rstudio,pssguy/rstudio,thklaus/rstudio,vbelakov/rstudio,pssguy/rstudio,thklaus/rstudio,sfloresm/rstudio,sfloresm/rstudio,brsimioni/rstudio,tbarrongh/rstudio,JanMarvin/rstudio,edrogers/rstudio,piersharding/rstudio,piersharding/rstudio,vbelakov/rstudio,vbelakov/rstudio,pssguy/rstudio,jar1karp/rstudio,tbarrongh/rstudio,john-r-mcpherson/rstudio,more1/rstudio,suribes/rstudio,jrnold/rstudio,brsimioni/rstudio,brsimioni/rstudio,jzhu8803/rstudio,pssguy/rstudio,JanMarvin/rstudio,jar1karp/rstudio,john-r-mcpherson/rstudio,vbelakov/rstudio,vbelakov/rstudio,jar1karp/rstudio,more1/rstudio,john-r-mcpherson/rstudio,more1/rstudio,vbelakov/rstudio,jar1karp/rstudio,githubfun/rstudio,piersharding/rstudio,pssguy/rstudio,edrogers/rstudio,tbarrongh/rstudio,jrnold/rstudio,jrnold/rstudio,jrnold/rstudio,sfloresm/rstudio,githubfun/rstudio,JanMarvin/rstudio,jzhu8803/rstudio,jzhu8803/rstudio,pssguy/rstudio,piersharding/rstudio,githubfun/rstudio,more1/rstudio,JanMarvin/rstudio,suribes/rstudio,suribes/rstudio,tbarrongh/rstudio,john-r-mcpherson/rstudio,JanMarvin/rstudio,jar1karp/rstudio,jzhu8803/rstudio,piersharding/rstudio,thklaus/rstudio,tbarrongh/rstudio,jar1karp/rstudio,more1/rstudio,suribes/rstudio,piersharding/rstudio,jrnold/rstudio,sfloresm/rstudio,jzhu8803/rstudio,githubfun/rstudio,suribes/rstudio,vbelakov/rstudio,more1/rstudio,thklaus/rstudio,edrogers/rstudio,suribes/rstudio,jar1karp/rstudio,githubfun/rstudio,jrnold/rstudio,john-r-mcpherson/rstudio,john-r-mcpherson/rstudio,tbarrongh/rstudio,jzhu8803/rstudio,githubfun/rstudio,jzhu8803/rstudio,piersharding/rstudio,jar1karp/rstudio,edrogers/rstudio,piersharding/rstudio,pssguy/rstudio,edrogers/rstudio,suribes/rstudio,sfloresm/rstudio,piersharding/rstudio,john-r-mcpherson/rstudio,sfloresm/rstudio,edrogers/rstudio,edrogers/rstudio,jzhu8803/rstudio,tbarrongh/rstudio,brsimioni/rstudio,thklaus/rstudio,suribes/rstudio,JanMarvin/rstudio,jrnold/rstudio,JanMarvin/rstudio,thklaus/rstudio,tbarrongh/rstudio,githubfun/rstudio,githubfun/rstudio,more1/rstudio,thklaus/rstudio,JanMarvin/rstudio,more1/rstudio,brsimioni/rstudio,jar1karp/rstudio,JanMarvin/rstudio