Generate Typeable info at definition sites

This is the second attempt at merging D757.

This patch implements the idea floated in Trac #9858, namely that we
should generate type-representation information at the data type
declaration site, rather than when solving a Typeable constraint.

However, this turned out quite a bit harder than I expected. I still
think it's the right thing to do, and it's done now, but it was quite
a struggle.

See particularly

 * Note [Grand plan for Typeable] in TcTypeable (which is a new module)
 * Note [The overall promotion story] in DataCon (clarifies existing
stuff)

The most painful bit was that to generate Typeable instances (ie
TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
etc:

 * We need to have enough data types around to *define* a TyCon
 * Many of these types are wired-in

Also, to minimise the code generated for each data type, I wanted to
generate pure data, not CAFs with unpackCString# stuff floating about.

Performance
~~~~~~~~~~~
Three perf/compiler tests start to allocate quite a bit more. This isn't
surprising, because they all allocate zillions of data types, with
practically no other code, esp. T1969

 * T1969:    GHC allocates 19% more
 * T4801:    GHC allocates 13% more
 * T5321FD:  GHC allocates 13% more
 * T9675:    GHC allocates 11% more
 * T783:     GHC allocates 11% more
 * T5642:    GHC allocates 10% more

I'm treating this as acceptable. The payoff comes in Typeable-heavy
code.

Remaining to do
~~~~~~~~~~~~~~~

 * I think that "TyCon" and "Module" are over-generic names to use for
   the runtime type representations used in GHC.Typeable. Better might
be
   "TrTyCon" and "TrModule". But I have not yet done this

 * Add more info the the "TyCon" e.g. source location where it was
   defined

 * Use the new "Module" type to help with Trac Trac #10068

 * It would be possible to generate TyConRepName (ie Typeable
   instances) selectively rather than all the time. We'd need to persist
   the information in interface files. Lacking a motivating reason I
have
   not done this, but it would not be difficult.

Refactoring
~~~~~~~~~~~
As is so often the case, I ended up refactoring more than I intended.
In particular

 * In TyCon, a type *family* (whether type or data) is repesented by a
   FamilyTyCon
     * a algebraic data type (including data/newtype instances) is
       represented by AlgTyCon This wasn't true before; a data family
       was represented as an AlgTyCon. There are some corresponding
       changes in IfaceSyn.

     * Also get rid of the (unhelpfully named) tyConParent.

 * In TyCon define 'Promoted', isomorphic to Maybe, used when things are
   optionally promoted; and use it elsewhere in GHC.

 * Cleanup handling of knownKeyNames

 * Each TyCon, including promoted TyCons, contains its TyConRepName, if
   it has one. This is, in effect, the name of its Typeable instance.

Updates haddock submodule

Test Plan: Let Harbormaster validate

Reviewers: austin, hvr, goldfire

Subscribers: goldfire, thomie

Differential Revision: https://phabricator.haskell.org/D1404

GHC Trac Issues: #9858

7 files changed, 9 insertions, 0 deletions

diff --git a/testsuite/tests/stranal/sigs/BottomFromInnerLambda.stderr b/testsuite/tests/stranal/sigs/BottomFromInnerLambda.stderr
index e8ae690147..4bc1e3f379 100644
--- a/testsuite/tests/stranal/sigs/BottomFromInnerLambda.stderr
+++ b/testsuite/tests/stranal/sigs/BottomFromInnerLambda.stderr
@@ -1,5 +1,6 @@
 
 ==================== Strictness signatures ====================
+BottomFromInnerLambda.$trModule: m
 BottomFromInnerLambda.expensive: <S(S),1*U(U)>m
 BottomFromInnerLambda.f: <S(S),1*U(U)>
 
diff --git a/testsuite/tests/stranal/sigs/DmdAnalGADTs.stderr b/testsuite/tests/stranal/sigs/DmdAnalGADTs.stderr
index 7fb1a55223..aa7a2ef8b6 100644
--- a/testsuite/tests/stranal/sigs/DmdAnalGADTs.stderr
+++ b/testsuite/tests/stranal/sigs/DmdAnalGADTs.stderr
@@ -1,5 +1,7 @@
 
 ==================== Strictness signatures ====================
+DmdAnalGADTs.$tcD: m
+DmdAnalGADTs.$trModule: m
 DmdAnalGADTs.diverges: b
 DmdAnalGADTs.f: <S,1*U>
 DmdAnalGADTs.f': <S,1*U>m
diff --git a/testsuite/tests/stranal/sigs/HyperStrUse.stderr b/testsuite/tests/stranal/sigs/HyperStrUse.stderr
index 1a0ff337c1..f04a2118fd 100644
--- a/testsuite/tests/stranal/sigs/HyperStrUse.stderr
+++ b/testsuite/tests/stranal/sigs/HyperStrUse.stderr
@@ -1,5 +1,6 @@
 
 ==================== Strictness signatures ====================
+HyperStrUse.$trModule: m
 HyperStrUse.f: <S(SL),1*U(1*U(U),A)><S,1*U>m
 
 
diff --git a/testsuite/tests/stranal/sigs/StrAnalExample.stderr b/testsuite/tests/stranal/sigs/StrAnalExample.stderr
index dbe4770080..bd82226bee 100644
--- a/testsuite/tests/stranal/sigs/StrAnalExample.stderr
+++ b/testsuite/tests/stranal/sigs/StrAnalExample.stderr
@@ -1,5 +1,6 @@
 
 ==================== Strictness signatures ====================
+StrAnalExample.$trModule: m
 StrAnalExample.foo: <S,1*U>
 
 
diff --git a/testsuite/tests/stranal/sigs/T8569.stderr b/testsuite/tests/stranal/sigs/T8569.stderr
index d33935ee14..3013d769fb 100644
--- a/testsuite/tests/stranal/sigs/T8569.stderr
+++ b/testsuite/tests/stranal/sigs/T8569.stderr
@@ -1,5 +1,7 @@
 
 ==================== Strictness signatures ====================
+T8569.$tcRep: m
+T8569.$trModule: m
 T8569.addUp: <S,1*U><L,U>
 
 
diff --git a/testsuite/tests/stranal/sigs/T8598.stderr b/testsuite/tests/stranal/sigs/T8598.stderr
index 8de5d31a01..28d5dd0c7d 100644
--- a/testsuite/tests/stranal/sigs/T8598.stderr
+++ b/testsuite/tests/stranal/sigs/T8598.stderr
@@ -1,5 +1,6 @@
 
 ==================== Strictness signatures ====================
+T8598.$trModule: m
 T8598.fun: <S(S),1*U(U)>m
 
 
diff --git a/testsuite/tests/stranal/sigs/UnsatFun.stderr b/testsuite/tests/stranal/sigs/UnsatFun.stderr
index 6e6402bacc..5f2d27ff20 100644
--- a/testsuite/tests/stranal/sigs/UnsatFun.stderr
+++ b/testsuite/tests/stranal/sigs/UnsatFun.stderr
@@ -1,5 +1,6 @@
 
 ==================== Strictness signatures ====================
+UnsatFun.$trModule: m
 UnsatFun.f: <B,1*U(U)><B,A>b
 UnsatFun.g: <B,1*U(U)>b
 UnsatFun.g': <L,1*U(U)>