[Debugger] Add a ReturnValueScope to correctly handle return values in nested debug breaks.

src/runtime/runtime-debug.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/compiler.h"
 #include "src/debug/debug-coverage.h"
 #include "src/debug/debug-evaluate.h"
@@ skipping 10 matching lines @@
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
 namespace internal {
 
 RUNTIME_FUNCTION(Runtime_DebugBreak) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 0);
+  HandleScope scope(isolate);
+  ReturnValueScope result_scope(isolate->debug());
   isolate->debug()->set_return_value(*value);
 
   // Get the top-most JavaScript frame.
   JavaScriptFrameIterator it(isolate);
   isolate->debug()->Break(it.frame());
   return isolate->debug()->return_value();
 }
 
 RUNTIME_FUNCTION(Runtime_DebugBreakOnBytecode) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 0);
+  HandleScope scope(isolate);
+  ReturnValueScope result_scope(isolate->debug());
   isolate->debug()->set_return_value(*value);
 
   // Get the top-most JavaScript frame.
   JavaScriptFrameIterator it(isolate);
   isolate->debug()->Break(it.frame());
 
   // Return the handler from the original bytecode array.
   DCHECK(it.frame()->is_interpreted());
   InterpretedFrame* interpreted_frame =
       reinterpret_cast<InterpretedFrame*>(it.frame());
@@ skipping 1911 matching lines @@
 
 RUNTIME_FUNCTION(Runtime_DebugTogglePreciseCoverage) {
   SealHandleScope shs(isolate);
   CONVERT_BOOLEAN_ARG_CHECKED(enable, 0);
   Coverage::TogglePrecise(isolate, enable);
   return isolate->heap()->undefined_value();
 }
 
 }  // namespace internal
 }  // namespace v8