+bindTyVarsFV :: [LHsTyVarBndr RdrName]
+ -> ([LHsTyVarBndr Name] -> RnM (a, FreeVars))
+ -> RnM (a, FreeVars)
+bindTyVarsFV tyvars thing_inside
+ = bindTyVarsRn tyvars $ \ tyvars' ->
+ do { (res, fvs) <- thing_inside tyvars'
+ ; return (res, delFVs (map hsLTyVarName tyvars') fvs) }
+