Merge branch 'hsyl20/fix-keepcafs' into 'master'

Retain CAFs in the interpreter

See merge request !1

iserv-proxy.cabal

@@ -99,6 +99,9 @@ Executable iserv-proxy
 Executable iserv-proxy-interpreter
    Default-Language: Haskell2010
    Main-Is: Interpreter.hs
+   -- We need to pass -fkeep-cafs to ensure that the interpreter retains CAFs
+   -- Iserv and GHC do something similar.
+   ghc-options: -fkeep-cafs
    Build-Depends: base       >= 4   && < 5,
                   iserv-proxy