Format all tests.

tests/language/optimized_string_charat_test.dart

Index: tests/language/optimized_string_charat_test.dart
diff --git a/tests/language/optimized_string_charat_test.dart b/tests/language/optimized_string_charat_test.dart
index 176ecd44042335c5867b580a5fdd1fbb853d36a8..f3368fe53bf944f666b1647e559b8ebb8d175a38 100644
--- a/tests/language/optimized_string_charat_test.dart
+++ b/tests/language/optimized_string_charat_test.dart
@@ -19,7 +19,6 @@ test_const_str(i) {
   return "abc"[i];
 }
 
-
 test_const_index(s) {
   return s[0];
 }
@@ -63,6 +62,4 @@ main() {
   Expect.equals(new String.fromCharCodes([456]), test_charat(c, 1));
   Expect.equals(new String.fromCharCodes([789]), test_charat(c, 2));
   Expect.throws(() => test_charat(c, 3));
-
-
 }