Make arguments read only in strict mode.

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index c0976988ea3c077800842816c03981ee5cf7b248..8d88032eadbe4e5824f5af9b8e17b7111cb65805 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -747,6 +747,10 @@ FunctionLiteral* Parser::ParseLazy(Handle<SharedFunctionInfo> info,
                                scope);
     TemporaryScope temp_scope(&this->temp_scope_);
 
+    if (info->strict_mode()) {
+      temp_scope.EnableStrictMode();
+    }
+
     FunctionLiteralType type =
         info->is_expression() ? EXPRESSION : DECLARATION;
     bool ok = true;
@@ -3540,7 +3544,7 @@ FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
       end_pos = scanner().location().end_pos;
     }
 
-    // Validate strict mode.
+    // Strict mode.
     if (temp_scope_->StrictMode()) {
       if (IsEvalOrArguments(name)) {
         int position = function_token_position != RelocInfo::kNoPosition
@@ -3564,6 +3568,9 @@ FunctionLiteral* Parser::ParseFunctionLiteral(Handle<String> var_name,
         return NULL;
       }
       CheckOctalLiteral(start_pos, end_pos, CHECK_OK);
+
+      // In strict mode, arguments are const.
+      top_scope_->SetArgumentsConst();
     }
 
     FunctionLiteral* function_literal =