Simon Peyton Jones authored Apr 18, 2016 and niteria committed Jul 25, 2016

There should be no change in behaviour here

* Move splitDepVarsOfType(s) from Type to TcType

* Define data type TcType.TcDepVars, document what it means,
  and use it where appropriate, notably in splitDepVarsOfType(s)

* Use it in TcMType.quantifyTyVars and friends

(cherry picked from commit 17eb2419)