Ben Gamari authored Jan 20, 2016 and Ben Gamari committed Jan 20, 2016

Previously types defined by `GHC.Types` and `GHC.Prim` had their
`Typeable` representations manually defined in `GHC.Typeable.Internals`.
This was terrible, resulting in a great deal of boilerplate and a number
of bugs due to missing or inconsistent representations (see #11120).

Here we take a different tack, initially proposed by Richard Eisenberg:
We wire-in the `Module`, `TrName`, and `TyCon` types, allowing them to
be used in `GHC.Types`. We then allow the usual type representation
generation logic to handle this module.

`GHC.Prim`, on the other hand, is a bit tricky as it has no object code
of its own.  To handle this we instead place the type representations
for the types defined here in `GHC.Types`.

On the whole this eliminates several special-cases as well as a fair
amount of boilerplate from hand-written representations. Moreover, we
get full coverage of primitive types for free.

Test Plan: Validate

Reviewers: goldfire, simonpj, austin, hvr

Subscribers: goldfire, simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D1774

GHC Trac Issues: #11120