strings: make Split(s, "", n) faster
strings: make Split(s, "", n) faster

R=rsc
CC=golang-dev
http://codereview.appspot.com/223096

Committer: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

mhennings/marcohennings-go,Triskite/willstone-goclone,mhennings/marcohennings-go,scirelli/scirelli-go,mhennings/marcohennings-go,d0f/go-zh,scirelli/scirelli-go,sanjosh/sanjos100-tipc,d0f/go-zh,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,Triskite/willstone-goclone,npe9/noahevans-go9,d0f/go-zh,d0f/go-zh,Triskite/willstone-goclone,npe9/noahevans-go9,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,bryanxu/go-zh,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,Triskite/willstone-goclone,npe9/noahevans-go9,Triskite/willstone-goclone,d0f/go-zh,bryanxu/go-zh,scirelli/scirelli-go,bryanxu/go-zh,mhennings/marcohennings-go,npe9/noahevans-go9,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,webfd/go-zh,bryanxu/go-zh,scirelli/scirelli-go,rdp/rogerpack2005-golang,rflanagan/reginaldflanagan-project1,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,scirelli/scirelli-go,glycerine/jeaten-go-arrayof-structof,glycerine/jeaten-go-arrayof-structof,npe9/noahevans-go9,webfd/go-zh,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,bryanxu/go-zh,sanjosh/sanjos100-tipc,scirelli/scirelli-go,npe9/noahevans-go9,webfd/go-zh,rflanagan/reginaldflanagan-project1,Triskite/willstone-goclone,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,npe9/noahevans-go9,d0f/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,webfd/go-zh,rflanagan/reginaldflanagan-project1,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,bryanxu/go-zh,Triskite/willstone-goclone,d0f/go-zh,scirelli/scirelli-go,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,npe9/noahevans-go9,Triskite/willstone-goclone