Delete Breakpoint objects, fixing memory leak

runtime/tests/vm/vm.status

 # 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.
 
 # Issue 28198
 cc/IsolateReload_PendingUnqualifiedCall_InstanceToStatic: Fail, Crash, Timeout
 cc/IsolateReload_PendingUnqualifiedCall_StaticToInstance: Fail, Crash, Timeout
 cc/IsolateReload_PendingConstructorCall_AbstractToConcrete: Fail, Crash, Timeout
 cc/IsolateReload_PendingConstructorCall_ConcreteToAbstract: Fail, Crash, Timeout
 cc/IsolateReload_PendingStaticCall_DefinedToNSM: Fail, Crash, Timeout
@@ skipping 172 matching lines @@
 dart/spawn_shutdown_test: Skip  # VM Shutdown test
 dart/hello_fuchsia_test: SkipByDesign # This is a test for fuchsia OS
 
 [ ($runtime == vm || $runtime == dart_precompiled) && $mode == debug && $builder_tag == asan ]
 cc/Dart2JSCompileAll: SkipSlow  # Timeout.
 
 [ $builder_tag == asan ]
 cc/CodeImmutability: Fail,OK # Address Sanitizer turns a crash into a failure.
 
 [ $builder_tag == asan && $arch == x64 ]
-cc/Debug_DeleteBreakpoint: Fail # Issue 28348
-
 cc/IsolateReload_ChangeInstanceFormat7: Fail # Issue 28349
 cc/IsolateReload_ClassAdded: Fail # Issue 28349
 cc/IsolateReload_ComplexInheritanceChange: Fail # Issue 28349
 cc/IsolateReload_ConstFieldUpdate: Fail # Issue 28349
 cc/IsolateReload_ConstantIdentical: Fail # Issue 28349
 cc/IsolateReload_ConstructorChanged: Fail # Issue 28349
 cc/IsolateReload_DanglingGetter_Class: Fail # Issue 28349
 cc/IsolateReload_DanglingGetter_Instance: Fail # Issue 28349
 cc/IsolateReload_DanglingGetter_Library: Fail # Issue 28349
 cc/IsolateReload_DanglingSetter_Class: Fail # Issue 28349
@@ skipping 91 matching lines @@
 cc/UseDartApi: Pass,Crash # Issue 28499
 
 [ $hot_reload || $hot_reload_rollback ]
 dart/spawn_shutdown_test: Skip # We can shutdown an isolate before it reloads.
 dart/spawn_infinite_loop_test: Skip # We can shutdown an isolate before it reloads.
 
 [ $arch == simdbc  || $arch == simdbc64 ]
 cc/Debugger_RewindOneFrame_Unoptimized: Skip # Issue 27878
 cc/Debugger_RewindTwoFrames_Unoptimized: Skip # Issue 27878
 cc/Debugger_Rewind_Optimized: Skip # Issue 27878