Fix missing escaping-kind check in tcPatSynSig

Note [Escaping kind in type signatures] explains how we deal
with escaping kinds in type signatures, e.g.
    f :: forall r (a :: TYPE r). a
where the kind of the body is (TYPE r), but `r` is not in
scope outside the forall-type.

I had missed this subtlety in tcPatSynSig, leading to #24686.
This MR fixes it; and a similar bug in tc_top_lhs_type. (The
latter is tested by T24686a.)