This is a temporary fix that will be reworked in a follow up commit
that aims to eliminate the tfExplicit flag from the compiler. The
complete and proper fix was considered too risky for inclusion just
before our 0.19 release.
This also makes the first baby steps towards a sound treatment of
higher-order kinds (type type int).
Adds test cases showcasing the new features.
* Also fixes breakage after the rebase
