Fix bug #3621, using fold_left2 on arrays of the same size only.
Fix bug #3621, using fold_left2 on arrays of the same size only.

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