Make safe points in generated code invisible to the debugger

runtime/vm/debugger_api_impl_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_debugger_api.h"
 #include "include/dart_mirrors_api.h"
 #include "platform/assert.h"
 #include "vm/dart_api_impl.h"
 #include "vm/thread.h"
 #include "vm/unit_test.h"
@@ skipping 634 matching lines @@
   int64_t int_value = ToInt64(retval);
   EXPECT_EQ(2, int_value);
   EXPECT(breakpoint_hit == true);
 }
 
 static const char* step_into_expected_bpts[] = {
     "main",
       "foo",
         "f1",
       "foo",
-        "X.X.",
-        "X.X.",
       "foo",
         "X.kvmk",
           "f2",
         "X.kvmk",
         "X.kvmk",
       "foo",
     "main"
 };
 
 void TestStepIntoHandler(Dart_IsolateId isolate_id,
@@ skipping 1396 matching lines @@
 
   Dart_Handle list_type = Dart_InstanceGetType(list_access_test_obj);
   Dart_Handle super_type = Dart_GetSupertype(list_type);
   EXPECT(!Dart_IsError(super_type));
   super_type = Dart_GetSupertype(super_type);
   EXPECT(!Dart_IsError(super_type));
   EXPECT(super_type == Dart_Null());
 }
 
 }  // namespace dart