Verify/document assumption about stack resource addresses.

runtime/vm/simulator_arm64.cc

 // Copyright (c) 2014, 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 <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM64)
 
@@ skipping 3465 matching lines @@
   SimulatorSetjmpBuffer* buf = last_setjmp_buffer();
   while (buf->link() != NULL && buf->link()->sp() <= sp) {
     buf = buf->link();
   }
   ASSERT(buf != NULL);
 
   // The C++ caller has not cleaned up the stack memory of C++ frames.
   // Prepare for unwinding frames by destroying all the stack resources
   // in the previous C++ frames.
   uword native_sp = buf->native_sp();
-  while (isolate->top_resource() != NULL &&
-         (reinterpret_cast<uword>(isolate->top_resource()) < native_sp)) {
-    isolate->top_resource()->~StackResource();
-  }
+  StackResource::Unwind(isolate, native_sp);
 
   // Unwind the C++ stack and continue simulation in the target frame.
   set_pc(static_cast<int64_t>(pc));
   set_register(NULL, SP, static_cast<int64_t>(sp));
   set_register(NULL, FP, static_cast<int64_t>(fp));
   // Set the tag.
   isolate->set_vm_tag(VMTag::kDartTagId);
   // Clear top exit frame.
   isolate->set_top_exit_frame_info(0);
 
   ASSERT(raw_exception != Object::null());
   set_register(NULL, kExceptionObjectReg, bit_cast<int64_t>(raw_exception));
   set_register(NULL, kStackTraceObjectReg, bit_cast<int64_t>(raw_stacktrace));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM64)
 
 #endif  // defined TARGET_ARCH_ARM64