Small code reorganization and moving around in ssrfwd.
Small code reorganization and moving around in ssrfwd.

SkySkimmer/coq,Zimmi48/coq,SkySkimmer/coq,Zimmi48/coq,coq/coq,SkySkimmer/coq,Zimmi48/coq,coq/coq,ejgallego/coq,SkySkimmer/coq,ejgallego/coq,ejgallego/coq,Zimmi48/coq,ejgallego/coq,coq/coq,coq/coq