Revert "Unify and fix checkers for duplicate object literal properties."

test/preparser/preparser.status

Index: test/preparser/preparser.status
diff --git a/test/preparser/preparser.status b/test/preparser/preparser.status
index 9d69988f71f561da18fd92198092587e7380c38a..37512bdeedacbd940a7d7bbdd4f861b74a41d35c 100644
--- a/test/preparser/preparser.status
+++ b/test/preparser/preparser.status
@@ -27,6 +27,12 @@
 
 [
 [ALWAYS, {
+  # TODO(mstarzinger): Uhm, this is kind of embarrassing, but our parser
+  # does not catch some syntax errors with duplicate properties in object
+  # literals that our preparser actually caught. I will fix this glitch in a
+  # follow-up change.
+  'duplicate-property/*': [SKIP],
+
   # TODO(mstarzinger): This script parses but throws a TypeError when run.
   'non-alphanum': [FAIL],