Simplify the error handling of clenv_refine_in.
Simplify the error handling of clenv_refine_in.

We move out the wrapper to tweak the exception.

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