[interpreter] Simplify graph builder control flow simulation.

src/compiler/bytecode-branch-analysis.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/bytecode-branch-analysis.h"
 
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
@@ skipping 93 matching lines @@
 const ZoneVector<int>* BytecodeBranchAnalysis::ForwardBranchesTargetting(
     int offset) const {
   auto iterator = branch_infos_.find(offset);
   if (branch_infos_.end() != iterator) {
     return iterator->second->fore_edge_offsets();
   } else {
     return nullptr;
   }
 }
 
-void BytecodeBranchAnalysis::AddExceptionalBranch(int throw_offset,
-                                                  int handler_offset) {
-  DCHECK(is_reachable(handler_offset));     // Handler was marked reachable.
-  DCHECK_LT(throw_offset, handler_offset);  // Always a forward branch.
-  AddBranch(throw_offset, handler_offset);
-}
-
 void BytecodeBranchAnalysis::AddBranch(int source_offset, int target_offset) {
   BytecodeBranchInfo* branch_info = nullptr;
   auto iterator = branch_infos_.find(target_offset);
   if (branch_infos_.end() == iterator) {
     branch_info = new (zone()) BytecodeBranchInfo(zone());
     branch_infos_.insert(std::make_pair(target_offset, branch_info));
   } else {
     branch_info = iterator->second;
   }
   branch_info->AddBranch(source_offset, target_offset);
 }
 
 void BytecodeBranchAnalysis::AnalyzeExceptionHandlers() {
   HandlerTable* table = HandlerTable::cast(bytecode_array()->handler_table());
   for (int i = 0; i < table->NumberOfRangeEntries(); ++i) {
     reachable_.Add(table->GetRangeHandler(i));
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8