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

4 files changed, 8 insertions, 8 deletions

diff --git a/testsuite/tests/safeHaskell/ghci/p6.stderr b/testsuite/tests/safeHaskell/ghci/p6.stderr
index 74beb053ca..2e68cd9a60 100644
--- a/testsuite/tests/safeHaskell/ghci/p6.stderr
+++ b/testsuite/tests/safeHaskell/ghci/p6.stderr
@@ -3,7 +3,7 @@
     • Unacceptable result type in foreign declaration:
         Safe Haskell is on, all FFI imports must be in the IO monad
     • When checking declaration:
-        foreign import ccall safe "static sin" c_sin :: Double -> Double
+        foreign import ccall safe "sin" c_sin :: Double -> Double
 
 <interactive>:12:1: error:
     • Variable not in scope: c_sin :: Integer -> t
diff --git a/testsuite/tests/safeHaskell/safeLanguage/SafeLang08.stderr b/testsuite/tests/safeHaskell/safeLanguage/SafeLang08.stderr
index 7d06e2f11c..ae5d658619 100644
--- a/testsuite/tests/safeHaskell/safeLanguage/SafeLang08.stderr
+++ b/testsuite/tests/safeHaskell/safeLanguage/SafeLang08.stderr
@@ -3,5 +3,5 @@ SafeLang08.hs:9:1:
     Unacceptable result type in foreign declaration:
       Safe Haskell is on, all FFI imports must be in the IO monad
     When checking declaration:
-      foreign import ccall safe "static SafeLang08_A" c_sin
+      foreign import ccall safe "SafeLang08_A" c_sin
         :: CDouble -> CDouble
diff --git a/testsuite/tests/safeHaskell/safeLanguage/SafeLang10.stderr b/testsuite/tests/safeHaskell/safeLanguage/SafeLang10.stderr
index d0c5c68d6a..557c4f4858 100644
--- a/testsuite/tests/safeHaskell/safeLanguage/SafeLang10.stderr
+++ b/testsuite/tests/safeHaskell/safeLanguage/SafeLang10.stderr
@@ -15,6 +15,6 @@ SafeLang10.hs:8:13:
     In the expression: res [(1 :: Int)]
     In an equation for ‘r’: r = res [(1 :: Int)]
     In the expression:
-      do { let r = res ...;
-           putStrLn $ "Result: " ++ show r;
-           putStrLn $ "Result: " ++ show function }
+      do let r = res ...
+         putStrLn $ "Result: " ++ show r
+         putStrLn $ "Result: " ++ show function
diff --git a/testsuite/tests/safeHaskell/safeLanguage/SafeLang17.stderr b/testsuite/tests/safeHaskell/safeLanguage/SafeLang17.stderr
index c59f86670a..3585721654 100644
--- a/testsuite/tests/safeHaskell/safeLanguage/SafeLang17.stderr
+++ b/testsuite/tests/safeHaskell/safeLanguage/SafeLang17.stderr
@@ -15,6 +15,6 @@ SafeLang17.hs:8:13:
     In the expression: res [(1 :: Int)]
     In an equation for ‘r’: r = res [(1 :: Int)]
     In the expression:
-      do { let r = res ...;
-           putStrLn $ "Result: " ++ show r;
-           putStrLn $ "Result: " ++ show function }
+      do let r = res ...
+         putStrLn $ "Result: " ++ show r
+         putStrLn $ "Result: " ++ show function