Fix 'eval' in class extends clauses to be always-strict

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/ast-graph-builder.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
@@ skipping 3062 matching lines @@
     environment()->Pop();
   } else if (ast_context()->IsTest()) {
     environment()->Poke(0, jsgraph()->FalseConstant());
   }
   compare_if.End();
   ast_context()->ReplaceValue();
 }
 
 
 LanguageMode AstGraphBuilder::language_mode() const {
-  return info()->language_mode();
+  return current_scope()->language_mode();
 }
 
 
 VectorSlotPair AstGraphBuilder::CreateVectorSlotPair(
     FeedbackVectorSlot slot) const {
   return VectorSlotPair(handle(info()->shared_info()->feedback_vector()), slot);
 }
 
 
 void AstGraphBuilder::VisitRewritableExpression(RewritableExpression* node) {
@@ skipping 1241 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8