Add dart analyzer test suite 'analyze_library' that fails if we

samples/tests/dartc/test_config.dart

Index: samples/tests/dartc/test_config.dart
diff --git a/samples/tests/dartc/test_config.dart b/samples/tests/dartc/test_config.dart
index a49af17e1324cb1f6fe7b5ac609c0db446f650f6..30368b8619ff973b791317a220315bbc9e20c879 100644
--- a/samples/tests/dartc/test_config.dart
+++ b/samples/tests/dartc/test_config.dart
@@ -38,12 +38,7 @@ class SamplesDartcTestSuite extends DartcCompilationTestSuite {
               ['samples/tests/dartc/dartc.status']);
 
   bool isTestFile(String filename) {
-    if (!filename.endsWith(".dart")) return false;
-    // Using readOptionsFromFile here causes the file to be read twice,
-    // because readOptionsFromFile is called again in the superclass.
-    // Avoid this in new code.
-    return StandardTestSuite.readOptionsFromFile(new Path(filename))
-        ["containsLeadingHash"];
+    return filename.endsWith(".dart");
   }
 
   bool get listRecursively => true;