Add HsSyn prettyprinter tests

Summary:
Add prettyprinter tests, which take a file, parse it, pretty print it,
re-parse the pretty printed version and then compare the original and
new ASTs (ignoring locations)

Updates haddock submodule to match the AST changes.

There are three issues outstanding

1. Extra parens around a context are not reproduced. This will require an
   AST change and will be done in a separate patch.

2. Currently if an `HsTickPragma` is found, this is not pretty-printed,
   to prevent noise in the output.

   I am not sure what the desired behaviour in this case is, so have left
   it as before. Test Ppr047 is marked as expected fail for this.

3. Apart from in a context, the ParsedSource AST keeps all the parens from
   the original source.  Something is happening in the renamer to remove the
   parens around visible type application, causing T12530 to fail, as the
   dumped splice decl is after the renamer.

   This needs to be fixed by keeping the parens, but I do not know where they
   are being removed.  I have amended the test to pass, by removing the parens
   in the expected output.

Test Plan: ./validate

Reviewers: goldfire, mpickering, simonpj, bgamari, austin

Reviewed By: simonpj, bgamari

Subscribers: simonpj, goldfire, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D2752

GHC Trac Issues: #3384

3 files changed, 12 insertions, 13 deletions

diff --git a/testsuite/tests/dependent/should_fail/PromotedClass.stderr b/testsuite/tests/dependent/should_fail/PromotedClass.stderr
index 544124ed07..f0683309bc 100644
--- a/testsuite/tests/dependent/should_fail/PromotedClass.stderr
+++ b/testsuite/tests/dependent/should_fail/PromotedClass.stderr
@@ -1,6 +1,5 @@
 
 PromotedClass.hs:10:15: error:
     • Illegal constraint in a type: Show a0
-    • In the first argument of ‘Proxy’, namely ‘MkX True’
-      In the type signature:
-        foo :: Proxy (MkX True)
+    • In the first argument of ‘Proxy’, namely ‘( 'MkX  'True)’
+      In the type signature: foo :: Proxy ( 'MkX  'True)
diff --git a/testsuite/tests/dependent/should_fail/RAE_T32a.stderr b/testsuite/tests/dependent/should_fail/RAE_T32a.stderr
index 1a54c7d53b..cb94dd2854 100644
--- a/testsuite/tests/dependent/should_fail/RAE_T32a.stderr
+++ b/testsuite/tests/dependent/should_fail/RAE_T32a.stderr
@@ -15,5 +15,5 @@ RAE_T32a.hs:28:20: error:
 
 RAE_T32a.hs:28:27: error:
     Expected kind ‘Sigma’, but ‘Sigma p r’ has kind ‘*’
-    In the second argument of ‘Sing’, namely ‘Sigma p r’
+    In the second argument of ‘Sing’, namely ‘(Sigma p r)’
     In the data instance declaration for ‘Sing’
diff --git a/testsuite/tests/dependent/should_fail/T11334b.stderr b/testsuite/tests/dependent/should_fail/T11334b.stderr
index 8f4251b0cd..effdf20828 100644
--- a/testsuite/tests/dependent/should_fail/T11334b.stderr
+++ b/testsuite/tests/dependent/should_fail/T11334b.stderr
@@ -3,22 +3,22 @@ T11334b.hs:8:14: error:
     • Cannot default kind variable ‘f0’
       of kind: k0 -> *
       Perhaps enable PolyKinds or add a kind signature
-    • In an expression type signature: Proxy Compose
-      In the expression: Proxy :: Proxy Compose
-      In an equation for ‘p’: p = Proxy :: Proxy Compose
+    • In an expression type signature: Proxy 'Compose
+      In the expression: Proxy :: Proxy 'Compose
+      In an equation for ‘p’: p = Proxy :: Proxy 'Compose
 
 T11334b.hs:8:14: error:
     • Cannot default kind variable ‘g0’
       of kind: k10 -> k0
       Perhaps enable PolyKinds or add a kind signature
-    • In an expression type signature: Proxy Compose
-      In the expression: Proxy :: Proxy Compose
-      In an equation for ‘p’: p = Proxy :: Proxy Compose
+    • In an expression type signature: Proxy 'Compose
+      In the expression: Proxy :: Proxy 'Compose
+      In an equation for ‘p’: p = Proxy :: Proxy 'Compose
 
 T11334b.hs:8:14: error:
     • Cannot default kind variable ‘a0’
       of kind: k10
       Perhaps enable PolyKinds or add a kind signature
-    • In an expression type signature: Proxy Compose
-      In the expression: Proxy :: Proxy Compose
-      In an equation for ‘p’: p = Proxy :: Proxy Compose
+    • In an expression type signature: Proxy 'Compose
+      In the expression: Proxy :: Proxy 'Compose
+      In an equation for ‘p’: p = Proxy :: Proxy 'Compose