use file-embed to make TH file embedding more robust

Haskell Language Server still struggles a bit with opening projects that
are subprojects of larger projects (in the git submodule sense).

When opening such projects from within their parent project, the overall
project path remains the outermost one, which breaks relative paths of
subprojects.

The file-embed has a utility to help with such path adjustments.
Theoretically, HLS will eventually support "multi-home units", where
different files will be compiled under different home folders if they
belong to subprojects, but in the meantime, this un-breaks HLS for users
that open Cryptol as a subproject of, say, SAW.

cryptol.cabal

@@ -58,11 +58,11 @@ library
                        deepseq           >= 1.3,
                        directory         >= 1.2.2.0,
                        exceptions,
+                       file-embed,
                        filepath          >= 1.3,
                        gitrev            >= 1.0,
                        ghc-prim,
                        GraphSCC          >= 1.0.4,
-                       heredoc           >= 0.2,
                        language-c99,
                        language-c99-simple,
                        libBF             >= 0.6 && < 0.7,

src/Cryptol/Prelude.hs

@@ -8,10 +8,9 @@
 --
 -- Compile the prelude into the executable as a last resort
 
-{-# LANGUAGE Safe #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TemplateHaskell #-}
 
 module Cryptol.Prelude
   ( preludeContents
@@ -23,28 +22,27 @@ module Cryptol.Prelude
   , cryptolTcContents
   ) where
 
-import Data.ByteString(ByteString)
+import Data.ByteString (ByteString)
+import Data.FileEmbed (embedFile, makeRelativeToProject)
 import qualified Data.ByteString.Char8 as B
-import Text.Heredoc (there)
-
 
 preludeContents :: ByteString
-preludeContents = B.pack [there|lib/Cryptol.cry|]
+preludeContents = $(makeRelativeToProject "lib/Cryptol.cry" >>= embedFile)
 
 preludeReferenceContents :: ByteString
-preludeReferenceContents = B.pack [there|lib/Cryptol/Reference.cry|]
+preludeReferenceContents = $(makeRelativeToProject "lib/Cryptol/Reference.cry" >>= embedFile)
 
 floatContents :: ByteString
-floatContents = B.pack [there|lib/Float.cry|]
+floatContents = $(makeRelativeToProject "lib/Float.cry" >>= embedFile)
 
 arrayContents :: ByteString
-arrayContents = B.pack [there|lib/Array.cry|]
+arrayContents = $(makeRelativeToProject "lib/Array.cry" >>= embedFile)
 
 suiteBContents :: ByteString
-suiteBContents = B.pack [there|lib/SuiteB.cry|]
+suiteBContents = $(makeRelativeToProject "lib/SuiteB.cry" >>= embedFile)
 
 primeECContents :: ByteString
-primeECContents = B.pack [there|lib/PrimeEC.cry|]
+primeECContents = $(makeRelativeToProject "lib/PrimeEC.cry" >>= embedFile)
 
 cryptolTcContents :: String
-cryptolTcContents = [there|lib/CryptolTC.z3|]
+cryptolTcContents = B.unpack $(makeRelativeToProject "lib/CryptolTC.z3" >>= embedFile)