Format all tests.

tests/language/vm/causal_async_exception_stack_test.dart

Index: tests/language/vm/causal_async_exception_stack_test.dart
diff --git a/tests/language/vm/causal_async_exception_stack_test.dart b/tests/language/vm/causal_async_exception_stack_test.dart
index 58c1938cf3dd921625d49cbc9294b89572b58d42..bccfcfb3891dc2262ce20b4b42e389a24768bf34 100644
--- a/tests/language/vm/causal_async_exception_stack_test.dart
+++ b/tests/language/vm/causal_async_exception_stack_test.dart
@@ -30,13 +30,13 @@ main() async {
     fail("Did not throw");
   } catch (e, st) {
     expect(st.toString(), stringContainsInOrder([
-        'thrower', '.dart:8',
-        '<asynchronous suspension>',
-        'generator', '.dart:17',
-        '<asynchronous suspension>',
-        'foo', '.dart:21',
-        '<asynchronous suspension>',
-        'main',
+        'thrower', '.dart:8',         //
+        '<asynchronous suspension>',  //
+        'generator', '.dart:17',      //
+        '<asynchronous suspension>',  //
+        'foo', '.dart:21',            //
+        '<asynchronous suspension>',  //
+        'main',                       //
         ]));
   }
 
@@ -68,9 +68,9 @@ main() async {
     await thrower();
   } catch(e, st) {
     expect(st.toString(), stringContainsInOrder([
-           'thrower', '.dart:8',
-           '<asynchronous suspension>',
-           'main', '.dart:68',
+           'thrower', '.dart:8',         //
+           '<asynchronous suspension>',  //
+           'main', '.dart:68',           //
            ]));
   }
 }