Visible kind application

Summary:
This patch implements visible kind application (GHC Proposal 15/#12045), as well as #15360 and #15362.
It also refactors unnamed wildcard handling, and requires that type equations in type families in Template Haskell be
written with full type on lhs. PartialTypeSignatures are on and warnings are off automatically with visible kind
application, just like in term-level.

There are a few remaining issues with this patch, as documented in
ticket #16082.

Includes a submodule update for Haddock.

Test Plan: Tests T12045a/b/c/TH1/TH2, T15362, T15592a

Reviewers: simonpj, goldfire, bgamari, alanz, RyanGlScott, Iceland_jack

Subscribers: ningning, Iceland_jack, RyanGlScott, int-index, rwbarton, mpickering, carter

GHC Trac Issues: `#12045`, `#15362`, `#15592`, `#15788`, `#15793`, `#15795`, `#15797`, `#15799`, `#15801`, `#15807`, `#15816`

Differential Revision: https://phabricator.haskell.org/D5229

1 files changed, 19 insertions, 15 deletions

diff --git a/testsuite/tests/partial-sigs/should_compile/SplicesUsed.stderr b/testsuite/tests/partial-sigs/should_compile/SplicesUsed.stderr
index ea974895e2..88fc8d50b9 100644
--- a/testsuite/tests/partial-sigs/should_compile/SplicesUsed.stderr
+++ b/testsuite/tests/partial-sigs/should_compile/SplicesUsed.stderr
@@ -3,12 +3,13 @@
 
 SplicesUsed.hs:7:16: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘Maybe Bool’
-    • In the type signature: maybeBool :: (_)
+    • In the type ‘_’
+      In the type signature: maybeBool :: (_)
 
 SplicesUsed.hs:8:15: warning: [-Wpartial-type-signatures (in -Wdefault)]
-    • Found type wildcard ‘_a’ standing for ‘w’
-      Where: ‘w’ is a rigid type variable bound by
-               the inferred type of <expression> :: w -> w
+    • Found type wildcard ‘_a’ standing for ‘_’
+      Where: ‘_’ is a rigid type variable bound by
+               the inferred type of <expression> :: _ -> _
                at SplicesUsed.hs:8:15-22
     • In an expression type signature: _a -> _a
       In the expression: id :: _a -> _a
@@ -18,10 +19,9 @@ SplicesUsed.hs:8:15: warning: [-Wpartial-type-signatures (in -Wdefault)]
 
 SplicesUsed.hs:8:27: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘Bool’
-    • In an expression type signature: Maybe _
-      In the first argument of ‘id :: _a -> _a’, namely
-        ‘(Just True :: Maybe _)’
-      In the expression: (id :: _a -> _a) (Just True :: Maybe _)
+    • In the first argument of ‘Maybe’, namely ‘_’
+      In the type ‘Maybe _’
+      In an expression type signature: Maybe _
     • Relevant bindings include
         maybeBool :: Maybe Bool (bound at SplicesUsed.hs:8:1)
 
@@ -30,28 +30,32 @@ SplicesUsed.hs:10:17: warning: [-Wpartial-type-signatures (in -Wdefault)]
       Where: ‘a’ is a rigid type variable bound by
                the inferred type of charA :: a -> (Char, a)
                at SplicesUsed.hs:11:1-18
-    • In the type signature: charA :: a -> (_)
+    • In the type ‘a -> (_)’
+      In the type signature: charA :: a -> (_)
 
 SplicesUsed.hs:13:14: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘a -> Bool’
       Where: ‘a’ is a rigid type variable bound by
                the inferred type of filter' :: (a -> Bool) -> [a] -> [a]
                at SplicesUsed.hs:14:1-16
-    • In the type signature: filter' :: (_ -> _ -> _)
+    • In the type ‘_ -> _ -> _’
+      In the type signature: filter' :: (_ -> _ -> _)
 
 SplicesUsed.hs:13:14: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘[a]’
       Where: ‘a’ is a rigid type variable bound by
                the inferred type of filter' :: (a -> Bool) -> [a] -> [a]
                at SplicesUsed.hs:14:1-16
-    • In the type signature: filter' :: (_ -> _ -> _)
+    • In the type ‘_ -> _ -> _’
+      In the type signature: filter' :: (_ -> _ -> _)
 
 SplicesUsed.hs:13:14: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘[a]’
       Where: ‘a’ is a rigid type variable bound by
                the inferred type of filter' :: (a -> Bool) -> [a] -> [a]
                at SplicesUsed.hs:14:1-16
-    • In the type signature: filter' :: (_ -> _ -> _)
+    • In the type ‘_ -> _ -> _’
+      In the type signature: filter' :: (_ -> _ -> _)
 
 SplicesUsed.hs:16:3: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • Found type wildcard ‘_’ standing for ‘Eq a’
@@ -72,8 +76,8 @@ SplicesUsed.hs:18:3: warning: [-Wpartial-type-signatures (in -Wdefault)]
     • In the type signature: bar :: _a -> _b -> (_a, _b)
 
 SplicesUsed.hs:18:3: warning: [-Wpartial-type-signatures (in -Wdefault)]
-    • Found type wildcard ‘_b’ standing for ‘w’
-      Where: ‘w’ is a rigid type variable bound by
-               the inferred type of bar :: Bool -> w -> (Bool, w)
+    • Found type wildcard ‘_b’ standing for ‘_’
+      Where: ‘_’ is a rigid type variable bound by
+               the inferred type of bar :: Bool -> _ -> (Bool, _)
                at SplicesUsed.hs:18:3-10
     • In the type signature: bar :: _a -> _b -> (_a, _b)