[liveedit] reimplement frame restarting.

src/compiler/js-generic-lowering.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/compiler/js-generic-lowering.h"
 
 #include "src/ast/ast.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 650 matching lines @@
     if (use->opcode() == IrOpcode::kIfSuccess) {
       use->ReplaceUses(merge);
       merge->ReplaceInput(1, use);
     }
   }
 
   // Turn the stack check into a runtime call.
   ReplaceWithRuntimeCall(node, Runtime::kStackGuard);
 }
 
+void JSGenericLowering::LowerJSDebugger(Node* node) {
+  CallDescriptor::Flags flags = FrameStateFlagForCall(node);
+  Callable callable = CodeFactory::HandleDebuggerStatement(isolate());
+  ReplaceWithStubCall(node, callable, flags);
+}
 
 Zone* JSGenericLowering::zone() const { return graph()->zone(); }
 
 
 Isolate* JSGenericLowering::isolate() const { return jsgraph()->isolate(); }
 
 
 Graph* JSGenericLowering::graph() const { return jsgraph()->graph(); }
 
 
 CommonOperatorBuilder* JSGenericLowering::common() const {
   return jsgraph()->common();
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8