[es6] Tail calls support.

src/full-codegen/full-codegen.cc

 // Copyright 2012 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/full-codegen/full-codegen.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/ast-numbering.h"
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 1402 matching lines @@
 }
 
 
 void FullCodeGenerator::VisitCall(Call* expr) {
 #ifdef DEBUG
   // We want to verify that RecordJSReturnSite gets called on all paths
   // through this function.  Avoid early returns.
   expr->return_is_recorded_ = false;
 #endif
 
-  Comment cmnt(masm_, "[ Call");
+  Comment cmnt(masm_, expr->is_tail() ? "[ TailCall" : "[ Call");
   Expression* callee = expr->expression();
   Call::CallType call_type = expr->GetCallType(isolate());
 
   switch (call_type) {
     case Call::POSSIBLY_EVAL_CALL:
       EmitPossiblyEvalCall(expr);
       break;
     case Call::GLOBAL_CALL:
       EmitCallWithLoadIC(expr);
       break;
@@ skipping 296 matching lines @@
   return var->mode() == CONST_LEGACY || var->scope()->is_nonlinear() ||
          var->initializer_position() >= proxy->position();
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8