feat(third_party/bazel): Check in rules_haskell from Tweag

third_party/bazel/rules_haskell/tests/binary-with-compiler-flags/Main.hs

@@ -0,0 +1,13 @@
+-- Expects to pull -XStandaloneDeriving from the default compiler flags.
+module Main (main) where
+
+data Foo = Foo
+deriving instance Show Foo
+
+-- Expects -XLambdaCase to be passed via the 'compiler_flags' rule attribute.
+dummyId :: Foo -> Foo
+dummyId = \case
+  Foo -> Foo
+
+main :: IO ()
+main = print $ dummyId Foo