[TurboFan] Always enable deoptimization for BytecodeGraphBuilder.

src/compiler/bytecode-graph-builder.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-graph-builder.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/compilation-info.h"
 #include "src/compiler/compiler-source-position-table.h"
@@ skipping 485 matching lines @@
           FrameStateType::kInterpretedFunction,
           bytecode_array()->parameter_count(),
           bytecode_array()->register_count(), info->shared_info())),
       osr_ast_id_(info->osr_ast_id()),
       merge_environments_(local_zone),
       exception_handlers_(local_zone),
       current_exception_handler_(0),
       input_buffer_size_(0),
       input_buffer_(nullptr),
       exit_controls_(local_zone),
-      is_liveness_analysis_enabled_(FLAG_analyze_environment_liveness &&
-                                    info->is_deoptimization_enabled()),
+      is_liveness_analysis_enabled_(FLAG_analyze_environment_liveness),
       state_values_cache_(jsgraph),
       liveness_analyzer_(
           static_cast<size_t>(bytecode_array()->register_count()), true,
           local_zone),
       source_positions_(source_positions),
-      start_position_(info->shared_info()->start_position(), inlining_id) {}
+      start_position_(info->shared_info()->start_position(), inlining_id) {
+  // Bytecode graph builder assumes deoptimziation is enabled.
+  DCHECK(info->is_deoptimization_enabled());
+}
 
 Node* BytecodeGraphBuilder::GetNewTarget() {
   if (!new_target_.is_set()) {
     int params = bytecode_array()->parameter_count();
     int index = Linkage::GetJSCallNewTargetParamIndex(params);
     const Operator* op = common()->Parameter(index, "%new.target");
     Node* node = NewNode(op, graph()->start());
     new_target_.set(node);
   }
   return new_target_.get();
@@ skipping 1702 matching lines @@
         it->source_position().ScriptOffset(), start_position_.InliningId()));
     it->Advance();
   } else {
     DCHECK_GT(it->code_offset(), offset);
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8