Fix #15308 by suppressing invisble args more rigorously

Summary:
There was a buglet in `stripInvisArgs` (which is part of the
pretty-printing pipeline for types) in which only invisble arguments
which came before any visible arguments would be suppressed, but any
invisble arguments that came //after// visible ones would still be
printed, even if `-fprint-explicit-kinds`  wasn't enabled.
The fix is simple: make `stripInvisArgs` recursively process the
remaining types even after a visible argument is encountered.

Test Plan: make test TEST=T15308

Reviewers: goldfire, bgamari

Reviewed By: bgamari

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #15308

Differential Revision: https://phabricator.haskell.org/D4891