Remove corelib/corelib_strong and migrate last two remaining tests.

tests/corelib_2/linked_hash_map_from_iterable_test.dart

Index: tests/corelib_2/linked_hash_map_from_iterable_test.dart
diff --git a/tests/corelib/linked_hash_map_from_iterable_test.dart b/tests/corelib_2/linked_hash_map_from_iterable_test.dart
similarity index 97%
rename from tests/corelib/linked_hash_map_from_iterable_test.dart
rename to tests/corelib_2/linked_hash_map_from_iterable_test.dart
index 4b7f6b9f24d26169afb4df1da34f476269c9fdcf..ed348e76e47a740aab19f99dda161e517dffa4f4 100644
--- a/tests/corelib/linked_hash_map_from_iterable_test.dart
+++ b/tests/corelib_2/linked_hash_map_from_iterable_test.dart
@@ -101,7 +101,7 @@ void equalElementsTest() {
 }
 
 void genericTypeTest() {
-  var map = new LinkedHashMap<int, String>.fromIterable(<int>[1, 2, 3],
+  dynamic map = new LinkedHashMap<int, String>.fromIterable(<int>[1, 2, 3],
       value: (x) => '$x');
   Expect.isTrue(map is Map<int, String>);
   Expect.isTrue(map is LinkedHashMap<int, String>);