Mod_subst: an extra assert
Mod_subst: an extra assert

It seems that the Equiv delta_hint in a resolver have a particular shape:
a kn can apparently only be shifted to another kn with same label
this way. We validate this fact via an assert, since this isn't
obvious (due to recursive calls in Mod_subst and Modops), and since
this implies the important fact that user and canonical parts
of kernel pairs have necessarily the same label (and section dirpath).

git-svn-id: 44dc50bdcc0f5d1a212c497508dc9452e0b35e2b@16219 85f007b7-540e-0410-9357-904b9bb8a0f7

Lionel-Rieg/coq,amintimany/coq,gares/coq,Matafou/coq,silene/coq,barras/coq,shindere/coq,ppedrot/coq,letouzey/coq-wip,herbelin/github-coq,jpdeplaix/coq,maximedenes/coq,ppedrot/coq,amintimany/coq,ppedrot/coq,SkySkimmer/coq,mattam82/coq,letouzey/coq-wip,Zimmi48/coq,amintimany/coq,mattam82/coq,mlasson/coq,SkySkimmer/coq,TOSPIO/coq,pirapira/coq2rust,pirapira/coq2rust,letouzey/coq-wip,8l/coq,Lionel-Rieg/coq,maximedenes/coq,8l/coq,william-lawvere/coq,Ptival/coq,ppedrot/coq,gmalecha/coq,Matafou/coq,ale-f/coq,gmalecha/coq,asr/coq,ejgallego/coq,ejgallego/coq,ale-f/coq,maximedenes/coq,barras/coq,TheTypoMaster/coq,maximedenes/coq,coq/coq,Zimmi48/coq,shindere/coq,JasonGross/coq,william-lawvere/coq,jpdeplaix/coq,pirapira/coq2rust,TOSPIO/coq,gares/coq,jpdeplaix/coq,herbelin/github-coq,JasonGross/coq,Zimmi48/coq,SkySkimmer/coq,asr/coq,pirbo/coq,8l/coq,coq/coq,ale-f/coq,gares/coq,coq/coq,ejgallego/coq,mlasson/coq,Zimmi48/coq,SkySkimmer/coq,william-lawvere/coq,aspiwack/coq,JasonGross/coq,mattam82/coq,TOSPIO/coq,letouzey/coq-wip,aspiwack/coq,silene/coq,JasonGross/coq,pirbo/coq,Ptival/coq,ejgallego/coq,asr/coq,shindere/coq,aspiwack/coq,gmalecha/coq,letouzey/coq-wip,pirbo/coq,herbelin/github-coq,Lionel-Rieg/coq,Ptival/coq,TheTypoMaster/coq,coq/coq,maximedenes/coq,gares/coq,ppedrot/coq,Matafou/coq,TheTypoMaster/coq,mlasson/coq,gares/coq,barras/coq,silene/coq