Tacinterp: push_trace doesn't need to be wrapped in a tactic
Tacinterp: push_trace doesn't need to be wrapped in a tactic

This lets us get rid of dummy proofview manips.

Simplifications based on [(tclUNIT foo >>= f) = f foo]

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