Cache the number of data cons in DataTyCon and SumTyCon

This is a follow-up after faf60e85 - Make tagForCon non-linear.
On the mailing list @simonpj suggested to solve the
linear behavior by caching the sizes.

Test Plan: ./validate

Reviewers: simonpj, simonmar, bgamari, austin

Reviewed By: simonpj

Subscribers: carter, goldfire, rwbarton, thomie, simonpj

Differential Revision: https://phabricator.haskell.org/D4131

1 files changed, 1 insertions, 14 deletions

diff --git a/compiler/iface/BuildTyCl.hs b/compiler/iface/BuildTyCl.hs
index 3d34e6f5fd..113ec12b63 100644
--- a/compiler/iface/BuildTyCl.hs
+++ b/compiler/iface/BuildTyCl.hs
@@ -9,7 +9,7 @@ module BuildTyCl (
         buildDataCon,
         buildPatSyn,
         TcMethInfo, buildClass,
-        mkNewTyConRhs, mkDataTyConRhs,
+        mkNewTyConRhs,
         newImplicitBinder, newTyConRepName
     ) where
 
@@ -41,19 +41,6 @@ import UniqSupply
 import Util
 import Outputable
 
-mkDataTyConRhs :: [DataCon] -> AlgTyConRhs
-mkDataTyConRhs cons
-  = DataTyCon {
-        data_cons = cons,
-        is_enum = not (null cons) && all is_enum_con cons
-                  -- See Note [Enumeration types] in TyCon
-    }
-  where
-    is_enum_con con
-       | (_univ_tvs, ex_tvs, eq_spec, theta, arg_tys, _res)
-           <- dataConFullSig con
-       = null ex_tvs && null eq_spec && null theta && null arg_tys
-
 
 mkNewTyConRhs :: Name -> TyCon -> DataCon -> TcRnIf m n AlgTyConRhs
 -- ^ Monadic because it makes a Name for the coercion TyCon