MERGED: Compare the kinds of type variables when comparing types

    commit 2c207b6f

    Author: Simon Peyton Jones <simonpj@microsoft.com>
    Date:   Tue Oct 2 18:11:08 2012 +0100

    Compare the kinds of type variables when comparing types

    This is just a bug that's been around since we introduced
    polymorphic kinds.  The roots are in Type.cmpTypeX, but
    there was a variant in TcRnDriver.checkBootTyCon, which
    is where it came up.

    Fixes Trac #7272