[ignition] Replace branch+loop analysis with a single pass

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 {
-namespace internal {
-namespace compiler {
-
-BytecodeBranchAnalysis::BytecodeBranchAnalysis(
-    Handle<BytecodeArray> bytecode_array, Zone* zone)
-    : bytecode_array_(bytecode_array),
-      is_backward_target_(bytecode_array->length(), zone),
-      is_forward_target_(bytecode_array->length(), zone),
-      zone_(zone) {}
-
-void BytecodeBranchAnalysis::Analyze() {
-  interpreter::BytecodeArrayIterator iterator(bytecode_array());
-  while (!iterator.done()) {
-    interpreter::Bytecode bytecode = iterator.current_bytecode();
-    int current_offset = iterator.current_offset();
-    if (interpreter::Bytecodes::IsJump(bytecode)) {
-      AddBranch(current_offset, iterator.GetJumpTargetOffset());
-    }
-    iterator.Advance();
-  }
-}
-
-void BytecodeBranchAnalysis::AddBranch(int source_offset, int target_offset) {
-  if (source_offset < target_offset) {
-    is_forward_target_.Add(target_offset);
-  } else {
-    is_backward_target_.Add(target_offset);
-  }
-}
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8