Add pretty-print test

testsuite/tests/ghc-regress/typecheck/should_fail/all.T

@@ -162,3 +162,4 @@ test('tcfail173', normal, compile_fail, [''])
 test('tcfail174', normal, compile_fail, [''])
 test('tcfail175', normal, compile_fail, [''])
 test('tcfail176', normal, compile_fail, [''])
+test('tcfail177', normal, compile_fail, [''])

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail177.hs

+module ShouldFail where
+
+-- This is really a pretty-printer test, not a typechecker test
+-- The more infix ops we have, the worse fsep works
+
+allTests :: Bool
+allTests = foo
+           [a ~?= b
+           ,"Three" ~?= "3"
+           ,"Four" ~?= "4"
+           ,"Five" ~?= "5"
+           ,"Five" ~?= "5"
+           ,"Five" ~?= "5"
+           ,"Five" ~?= "5"
+           ,"Five" ~?= "5"
+           ,"Five" ~?= "5"
+           ,"Two", "Two", "Two" 
+           ,"Two", "Two", "Two" 
+           ,"Two", "Two", "Two" 
+           ,"Two", "Two", "Two" 
+           ,"Two", "Two", "Two" 
+           ,"Two", "Two", "Two"] 
+
+a=""
+b=""
+
+(~?=) :: a -> a -> Bool
+(~?=) = error "urk" 
+
+foo :: a -> Int
+foo x = 0

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail177.stderr

+*** Buggy output has incorrect indentation, but test harness discards
+*** white space, so doesn't show it up.  Hence this message, to force
+*** it to fail until we fix the bug.   
+
+tcfail177.hs:17:12:
+    Couldn't match expected type `Bool' against inferred type `[Char]'
+    In the expression: "Two"
+    In the first argument of `foo', namely
+	`[a ~?= b, "Three" ~?= "3", "Four" ~?= "4", "Five" ~?= "5",
+          "Five" ~?= "5", "Five" ~?= "5", "Five" ~?= "5", 
+	  "Five" ~?= "5", "Five" ~?= "5", "Two", "Two", "Two", 
+          "Two", "Two", "Two", "Two", "Two", "Two", "Two", "Two", 
+ 	  "Two", "Two", "Two", "Two", "Two", "Two", "Two"]'
+    In the expression:
+	foo
+	  [a ~?= b, "Three" ~?= "3", "Four" ~?= "4", "Five" ~?= "5",
+           "Five" ~?= "5", "Five" ~?= "5", "Five" ~?= "5", 
+	   "Five" ~?= "5", "Five" ~?= "5", "Two", "Two", "Two", 
+	   "Two", "Two", "Two", "Two", "Two", "Two", "Two", "Two", 
+	   "Two", "Two", "Two", "Two", "Two", "Two", "Two"]