Keep track of autos to be solved, shaves about 12% off of Elab.newt processing time

src/Lib/Types.newt

@@ -304,6 +304,7 @@ data MetaMode = CheckAll | CheckFirst | NoCheck
 record MetaContext where
   constructor MC
   metas : SortedMap QName MetaEntry
+  autos : List QName
   next : Int
   mcmode : MetaMode
 
@@ -370,7 +371,10 @@ record ModContext where
 
 -- A placeholder while walking through dependencies of a module
 emptyModCtx : String → ModContext
-emptyModCtx csum = MkModCtx csum EmptyMap (MC EmptyMap 0 NoCheck) EmptyMap
+emptyModCtx csum = MkModCtx csum EmptyMap (MC EmptyMap Nil 0 NoCheck) EmptyMap
+
+HintTable : U
+HintTable = SortedMap QName (List (QName × Tm))
 
 record TopContext where
   constructor MkTop
@@ -378,6 +382,8 @@ record TopContext where
   -- I'm putting a dummy entry in
   modules : SortedMap (List String) ModContext
   imported : List (List String)
+  -- TCon name → function name × type
+  hints : HintTable
 
   -- current module
   ns : List String