Avoid using is_ground_env in evarconv
Avoid using is_ground_env in evarconv

This should make the ephemeron-based memo not important (is_ground_env
is only used for program_inference_hook)

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