Type families: test for 1st half of #2203

testsuite/tests/ghc-regress/indexed-types/should_fail/Simple13.stderr

 
 Simple13.hs:9:0:
-    Illegal type family application in type instance: [C a]
+    Illegal type synonym family application in instance: [C a]
     In the data type instance declaration for `D'
 
 Simple13.hs:13:0:
-    Illegal type family application in type instance: [C a]
+    Illegal type synonym family application in instance: [C a]
     In the type synonym instance declaration for `E'

testsuite/tests/ghc-regress/indexed-types/should_fail/T2203a.hs

+{-# LANGUAGE ScopedTypeVariables, TypeFamilies, FlexibleInstances #-}
+
+module T2203a where
+
+class Foo a where
+   type TheFoo a
+   foo :: TheFoo a -> a
+   foo' :: a -> Int
+
+class Bar b where
+   bar :: b -> Int
+
+instance Foo a => Bar (Either a (TheFoo a)) where
+   bar (Left a) = foo' a
+   bar (Right b) = foo' (foo b :: a)

testsuite/tests/ghc-regress/indexed-types/should_fail/T2203a.stderr

+
+T2203a.hs:13:0:
+    Illegal type synonym family application in instance:
+        Either a (TheFoo a)
+    In the instance declaration for `Bar (Either a (TheFoo a))'

testsuite/tests/ghc-regress/indexed-types/should_fail/all.T

@@ -29,6 +29,7 @@ test('TyFamUndec', normal, compile_fail, [''])
 test('T2334', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])
 test('T1900', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])
 test('T2157', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])
+test('T2203a', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])
 
 test('GADTwrong1', if_compiler_lt('ghc', '6.9', expect_fail), compile_fail, [''])