Fix 5024 - diagnostic on unresolved catch types, added test case

tests/language/try_catch_on_syntax_test.dart

Index: tests/language/try_catch_on_syntax_test.dart
diff --git a/tests/language/try_catch_on_syntax_test.dart b/tests/language/try_catch_on_syntax_test.dart
index 4611f610ced335c9a1f665abf82f8503a9c7fdb8..e62f00f89cca518e7a877d84276d66374d47a73a 100644
--- a/tests/language/try_catch_on_syntax_test.dart
+++ b/tests/language/try_catch_on_syntax_test.dart
@@ -27,6 +27,8 @@ class TryCatchTest {
     } on MyException catch (e) {
       foo = 3;
     }
+    on UndefinedClass /// 07: compile-time error
+    catch(e) { foo = 4; }
     Expect.equals(2, foo);
   }