Add tests for the printf feature.
Add tests for the printf feature.

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