coqchk: use unsafe marshal for dependencies of -norec libraries
coqchk: use unsafe marshal for dependencies of -norec libraries

on test-suite/arithmetic/mod: 2.6s to 0.45s

coq/coq,coq/coq,Zimmi48/coq,ejgallego/coq,SkySkimmer/coq,silene/coq,SkySkimmer/coq,ppedrot/coq,ejgallego/coq,ejgallego/coq,ppedrot/coq,ppedrot/coq,coq/coq,gares/coq,gares/coq,ppedrot/coq,silene/coq,JasonGross/coq,gares/coq,SkySkimmer/coq,Matafou/coq,Zimmi48/coq,SkySkimmer/coq,silene/coq,Matafou/coq,JasonGross/coq,JasonGross/coq,JasonGross/coq,gares/coq,coq/coq,ppedrot/coq,Matafou/coq,Zimmi48/coq,Zimmi48/coq,ejgallego/coq,gares/coq