Track error message changes

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail016.stderr

 
 tcfail016.hs:9:17:
-    Couldn't match expected type `AnnExpr t'
-	   against inferred type `Expr t'
+    Couldn't match expected type `(t, Expr t)'
+           against inferred type `Expr t'
       Expected type: AnnExpr t -> [a]
       Inferred type: Expr t -> [[Char]]
     In the first argument of `(++)', namely `(g e1)'

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail168.stderr

 
 tcfail168.hs:8:10:
-    Couldn't match expected type `Char -> b'
-           against inferred type `IO b1'
+    Couldn't match expected type `IO ()'
+           against inferred type `Char -> ()'
     In a stmt of a 'do' expression: putChar 'a'
     In the expression:
         do putChar

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail186.stderr

 
 tcfail186.hs:7:8:
-    Couldn't match expected type `PhantomSyn a'
-	   against inferred type `[Char]'
+    Couldn't match expected type `Int' against inferred type `[Char]'
       Expected type: PhantomSyn a
       Inferred type: [Char]
     In the first argument of `f', namely `"hoo"'