Do not imply NoStarIsType by TypeOperators/TypeInType

Implementation of the "Embrace TypeInType" proposal was done according
to the spec, which specified that TypeOperators must imply NoStarIsType.
This implication was meant to prevent breakage and to be removed in 2
releases.  However, compiling head.hackage has shown that this
implication only magnified the breakage, so there is no reason to have
it in the first place.

To remain in compliance with the three-release policy, we add a
workaround to define the (*) type operator even when -XStarIsType is on.

Test Plan: ./validate

Reviewers: bgamari, RyanGlScott, goldfire, phadej, hvr

Reviewed By: bgamari, RyanGlScott

Subscribers: harpocrates, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4865