[turbofan] Added --csa-trap-on-node option that helps debugging graph verification issues.

src/compiler/code-assembler.cc

 // Copyright 2015 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/code-assembler.h"
 
 #include <ostream>
 
 #include "src/code-factory.h"
 #include "src/compiler/graph.h"
@@ skipping 47 matching lines @@
           InstructionSelector::AlignmentRequirements())),
       flags_(flags),
       name_(name),
       code_generated_(false),
       variables_(zone) {}
 
 CodeAssemblerState::~CodeAssemblerState() {}
 
 CodeAssembler::~CodeAssembler() {}
 
+class BreakOnNodeDecorator final : public GraphDecorator {
+ public:
+  explicit BreakOnNodeDecorator(NodeId node_id) : node_id_(node_id) {}
+
+  void Decorate(Node* node) final {
+    if (node->id() == node_id_) {
+      base::OS::DebugBreak();
+    }
+  }
+
+ private:
+  NodeId node_id_;
+};
+
+void CodeAssembler::BreakOnNode(int node_id) {
+  Graph* graph = raw_assembler()->graph();
+  Zone* zone = graph->zone();
+  GraphDecorator* decorator =
+      new (zone) BreakOnNodeDecorator(static_cast<NodeId>(node_id));
+  graph->AddDecorator(decorator);
+}
+
 void CodeAssembler::CallPrologue() {}
 
 void CodeAssembler::CallEpilogue() {}
 
 // static
 Handle<Code> CodeAssembler::GenerateCode(CodeAssemblerState* state,
                                          bool verify_graph) {
   // TODO(ishell): Remove verify_graph parameter and always enable the
   // verification once all the issues are fixed.
   DCHECK(!state->code_generated_);
@@ skipping 1116 matching lines @@
       }
     }
   }
 
   bound_ = true;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8