[es6] Add a flag to the Isolate that defines whether ES2015 tail call elimination is enabled or not.

src/external-reference-table.cc

 // Copyright 2016 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/external-reference-table.h"
 
 #include "src/accessors.h"
 #include "src/assembler.h"
 #include "src/counters.h"
 #include "src/deoptimizer.h"
@@ skipping 154 matching lines @@
   Add(ExternalReference::address_of_minus_one_half().address(),
       "double_constants.minus_one_half");
   Add(ExternalReference::stress_deopt_count(isolate).address(),
       "Isolate::stress_deopt_count_address()");
   Add(ExternalReference::virtual_handler_register(isolate).address(),
       "Isolate::virtual_handler_register()");
   Add(ExternalReference::virtual_slot_register(isolate).address(),
       "Isolate::virtual_slot_register()");
   Add(ExternalReference::runtime_function_table_address(isolate).address(),
       "Runtime::runtime_function_table_address()");
+  Add(ExternalReference::is_tail_call_elimination_enabled_address(isolate)
+          .address(),
+      "Isolate::is_tail_call_elimination_enabled_address()");
 
   // Debug addresses
   Add(ExternalReference::debug_after_break_target_address(isolate).address(),
       "Debug::after_break_target_address()");
   Add(ExternalReference::debug_is_active_address(isolate).address(),
       "Debug::is_active_address()");
   Add(ExternalReference::debug_step_in_enabled_address(isolate).address(),
       "Debug::step_in_enabled_address()");
 
 #ifndef V8_INTERPRETED_REGEXP
@@ skipping 159 matching lines @@
   for (int entry = 0; entry < kDeoptTableSerializeEntryCount; ++entry) {
     Address address = Deoptimizer::GetDeoptimizationEntry(
         isolate, entry, Deoptimizer::LAZY,
         Deoptimizer::CALCULATE_ENTRY_ADDRESS);
     Add(address, "lazy_deopt");
   }
 }
 
 }  // namespace internal
 }  // namespace v8