[Interpreter] Handles legacy constants in strict mode.

src/interpreter/bytecode-generator.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/interpreter/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "src/interpreter/control-flow-builders.h"
@@ skipping 2016 matching lines @@
           builder()
               ->JumpIfNotHole(&end_label)
               .LoadAccumulatorWithRegister(value_temp)
               .StoreContextSlot(context_reg, variable->index())
               .Bind(&end_label);
           builder()->LoadAccumulatorWithRegister(value_temp);
           // Break here because the value should not be stored unconditionally.
           // The above code performs the store conditionally.
           break;
         } else if (mode == CONST_LEGACY && op != Token::INIT) {
-          DCHECK(!is_strict(language_mode()));
           // Ensure accumulator is in the correct state.
           builder()->LoadAccumulatorWithRegister(value_temp);
           // Break here, non-initializing assignments to legacy constants are
           // ignored.
           break;
         } else {
           BuildHoleCheckForVariableAssignment(variable, op);
           builder()->LoadAccumulatorWithRegister(value_temp);
         }
       }
@@ skipping 1099 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8