Add SkipSlow marker

tests/language/assert_with_type_test_or_cast_test.dart

Index: tests/language/assert_with_type_test_or_cast_test.dart
diff --git a/tests/language/assert_with_type_test_or_cast_test.dart b/tests/language/assert_with_type_test_or_cast_test.dart
index e00d0d309ee8dbe17abc18c5515563d4620fa8cd..f9ec08bebfb15ed86061202743959c4a645bac84 100644
--- a/tests/language/assert_with_type_test_or_cast_test.dart
+++ b/tests/language/assert_with_type_test_or_cast_test.dart
@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 // Issue 3741: generic type tests and casts fail in assertion statements
-// when run in production mode.  
+// when run in production mode.

[ricow1, 2015/02/13 07:56:27]

This is unrelated to this, just removing whitespace + below

 //
 // The cause was incomplete generic type skipping, so each of the assert
 // statements below would fail.
@@ -13,16 +13,16 @@
 
 main() {
  var names = new List<int>();
- 
+
  // Generic type test.
  assert(names is List<int>);
- 
+
  // Negated generic type test.
  assert(names is !List<String>);
- 
+
  // Generic type cast.
  assert((names as List<num>).length == 0);
- 
+
  // Generic type test inside expression.
  assert((names is List<int>));
 }