crypto/sha1: mark block as non-escaping The compiler still gets the escape analysis wrong, but the annotation here is correct.
crypto/sha1: mark block as non-escaping
The compiler still gets the escape analysis wrong, but the annotation here is correct.

R=golang-dev, dave, bradfitz
CC=golang-dev
https://codereview.appspot.com/10514046

glycerine/jeaten-go-arrayof-structof,mhennings/marcohennings-go,bryanxu/go-zh,d0f/go-zh,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,webfd/go-zh,sanjosh/sanjos100-tipc,d0f/go-zh,rdp/rogerpack2005-golang,d0f/go-zh,d0f/go-zh,mhennings/marcohennings-go,webfd/go-zh,mhennings/marcohennings-go,d0f/go-zh,mhennings/marcohennings-go,webfd/go-zh,webfd/go-zh,rdp/rogerpack2005-golang,d0f/go-zh,rdp/rogerpack2005-golang,webfd/go-zh,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,mhennings/marcohennings-go,bryanxu/go-zh,rdp/rogerpack2005-golang,bryanxu/go-zh,bryanxu/go-zh,bryanxu/go-zh,webfd/go-zh,webfd/go-zh,bryanxu/go-zh,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,bryanxu/go-zh,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,d0f/go-zh,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof