runtime: add benchmark for complex128 division
runtime: add benchmark for complex128 division

R=golang-dev, dave, rsc
CC=golang-dev, minux.ma
http://codereview.appspot.com/6070043

Committer: Dave Cheney <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@cheney.net>

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