Migrate test block 10 to Dart 2.0.

tests/corelib_2/iterable_element_at_test.dart

Index: tests/corelib_2/iterable_element_at_test.dart
diff --git a/tests/corelib_strong/iterable_element_at_test.dart b/tests/corelib_2/iterable_element_at_test.dart
similarity index 83%
rename from tests/corelib_strong/iterable_element_at_test.dart
rename to tests/corelib_2/iterable_element_at_test.dart
index 364e94a5c8cf81566b412861965322547f7dc73d..b23085a47686670c0453be2e1c7243bdb9cecabe 100644
--- a/tests/corelib_strong/iterable_element_at_test.dart
+++ b/tests/corelib_2/iterable_element_at_test.dart
@@ -15,16 +15,14 @@ main() {
   Expect.equals(1, list1.elementAt(0));
   Expect.equals(2, list1.elementAt(1));
   Expect.equals(3, list1.elementAt(2));
-  Expect.throws(
-      () => list1.elementAt("2"), (e) => e is ArgumentError || e is TypeError);
+  list1.elementAt("2"); //# static: compile-time error
   Expect.throws(() => list1.elementAt(-1), (e) => e is ArgumentError);
   Expect.throws(() => list1.elementAt(3), (e) => e is RangeError);
 
   Expect.equals(4, list2.elementAt(0));
   Expect.equals(5, list2.elementAt(1));
   Expect.equals(6, list2.elementAt(2));
-  Expect.throws(
-      () => list2.elementAt("2"), (e) => e is ArgumentError || e is TypeError);
+  list2.elementAt("2"); //# static: compile-time error
   Expect.throws(() => list2.elementAt(-1), (e) => e is ArgumentError);
   Expect.throws(() => list2.elementAt(3), (e) => e is RangeError);
 
@@ -34,8 +32,7 @@ main() {
   Expect.throws(() => set1.elementAt(-1), (e) => e is ArgumentError);
   Expect.throws(() => set1.elementAt(3), (e) => e is RangeError);
 
-  Expect.throws(
-      () => set2.elementAt("2"), (e) => e is ArgumentError || e is TypeError);
+  set2.elementAt("2"); //# static: compile-time error
   Expect.throws(() => set2.elementAt(-1), (e) => e is ArgumentError);
   Expect.throws(() => set2.elementAt(0), (e) => e is RangeError);
   Expect.throws(() => set2.elementAt(1), (e) => e is RangeError);