It's not just [] that return the element type of a List. Make the container optimization work for s…

tests/compiler/dart2js/list_tracer_node_type_test.dart

Index: tests/compiler/dart2js/list_tracer_node_type_test.dart
===================================================================
--- tests/compiler/dart2js/list_tracer_node_type_test.dart	(revision 27800)
+++ tests/compiler/dart2js/list_tracer_node_type_test.dart	(working copy)
@@ -56,7 +56,16 @@
 }
 """;
 
+String generateTest(String call) {
+  return """
+main() {
+  var a = [42];
+  return a.$call + 42;
+}
+""";
+}
 
+
 main() {
   asyncTest(() => compileAll(TEST1).then((generated) {
     // Check that we only do a null check on the receiver for
@@ -88,4 +97,21 @@
   asyncTest(() => compileAll(TEST6).then((generated) {
     Expect.isFalse(generated.contains('iae'));
   }));
+
+  var selectors = const <String>[
+    'first',
+    'last',
+    'single',
+    'singleWhere',
+    'elementAt',
+    'removeAt',
+    'removeLast'
+  ];
+  selectors.map((name) => generateTest('$name()')).forEach((String test) {
+    asyncTest(() => compileAll(test).then((generated) {
+      Expect.isFalse(generated.contains('if (typeof t1'));
+      Expect.isFalse(generated.contains('if (t1 == null)'));
+    }));
+  });
+
 }