Build internal ghci support in Stage1

hadrian.cabal

@@ -91,6 +91,7 @@ executable hadrian
                        , Settings.Packages.Compiler
                        , Settings.Packages.Ghc
                        , Settings.Packages.GhcCabal
+                       , Settings.Packages.Ghci
                        , Settings.Packages.GhcPrim
                        , Settings.Packages.Haddock
                        , Settings.Packages.IntegerGmp

src/Settings/Default.hs

@@ -31,6 +31,7 @@ import Settings.Packages.Base
 import Settings.Packages.Compiler
 import Settings.Packages.Ghc
 import Settings.Packages.GhcCabal
+import Settings.Packages.Ghci
 import Settings.Packages.GhcPrim
 import Settings.Packages.Haddock
 import Settings.Packages.IntegerGmp
@@ -196,6 +197,7 @@ defaultPackageArgs = mconcat
     , compilerPackageArgs
     , ghcPackageArgs
     , ghcCabalPackageArgs
+    , ghciPackageArgs
     , ghcPrimPackageArgs
     , haddockPackageArgs
     , integerGmpPackageArgs

src/Settings/Packages/Ghci.hs

+module Settings.Packages.Ghci (ghciPackageArgs) where
+
+import GHC
+import Predicate
+
+ghciPackageArgs :: Args
+ghciPackageArgs = notStage0 ? package ghci ? builder GhcCabal ? arg "--flags=ghci"