Format all tests.

tests/language_strong/assign_op_test.dart

Index: tests/language_strong/assign_op_test.dart
diff --git a/tests/language_strong/assign_op_test.dart b/tests/language_strong/assign_op_test.dart
index 9a9ebe7086ddfaf73bcdbfd4df408aaa05262637..bc036e45515c7be16b5645c5603659e50e68e9f9 100644
--- a/tests/language_strong/assign_op_test.dart
+++ b/tests/language_strong/assign_op_test.dart
@@ -6,7 +6,6 @@
 
 import "package:expect/expect.dart";
 
-
 class AssignOpTest {
   AssignOpTest() {}
 
@@ -65,9 +64,9 @@ class AssignOpTest {
     Expect.equals(0xF8, x);
     x |= 0xF00;
     Expect.equals(0xFF8, x);
-    x &=0xF0;
+    x &= 0xF0;
     Expect.equals(0xF0, x);
-    x ^=0x11;
+    x ^= 0x11;
     Expect.equals(0xE1, x);
 
     var y = 100;
@@ -89,6 +88,7 @@ class AssignOpTest {
   static var f;
   var instf;
 }
+
 main() {
   for (int i = 0; i < 20; i++) {
     AssignOpTest.testMain();