Replace (SourceText,FastString) with StringLiteral data type

Summary:
Phab:D907 introduced SourceText for a number of data types, by replacing
FastString with (SourceText,FastString). Since this has an Outputable
instance, no warnings are generated when ppr is called on it, but
unexpected output is generated. See Phab:D1096 for an example of this.

Replace the (SourceText,FastString) tuples with a new data type,
```lang=hs
data StringLiteral = StringLiteral SourceText FastString
```

Update haddock submodule accordingly

Test Plan: ./validate

Reviewers: hvr, austin, rwbarton, trofi, bgamari

Reviewed By: trofi, bgamari

Subscribers: thomie, trofi, rwbarton, mpickering

Differential Revision: https://phabricator.haskell.org/D1101

GHC Trac Issues: #10692

1 files changed, 9 insertions, 0 deletions

diff --git a/compiler/utils/Binary.hs b/compiler/utils/Binary.hs
index f889a4c067..8f0d8e50dc 100644
--- a/compiler/utils/Binary.hs
+++ b/compiler/utils/Binary.hs
@@ -901,6 +901,15 @@ instance Binary WarningTxt where
                       d <- get bh
                       return (DeprecatedTxt s d)
 
+instance Binary StringLiteral where
+  put_ bh (StringLiteral st fs) = do
+            put_ bh st
+            put_ bh fs
+  get bh = do
+            st <- get bh
+            fs <- get bh
+            return (StringLiteral st fs)
+
 instance Binary a => Binary (GenLocated SrcSpan a) where
     put_ bh (L l x) = do
             put_ bh l