[es6] [interpreter] Add tail calls support to Ignition.

src/interpreter/bytecode-array-builder.h

 // 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.
 
 #ifndef V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include "src/ast/ast.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 146 matching lines @@
   // |context|.
   BytecodeArrayBuilder& PushContext(Register context);
 
   // Pop the current context and replace with |context|.
   BytecodeArrayBuilder& PopContext(Register context);
 
   // Call a JS function. The JSFunction or Callable to be called should be in
   // |callable|, the receiver should be in |receiver_args| and all subsequent
   // arguments should be in registers <receiver_args + 1> to
   // <receiver_args + receiver_arg_count - 1>.
-  BytecodeArrayBuilder& Call(Register callable, Register receiver_args,
-                             size_t receiver_arg_count, int feedback_slot);
+  BytecodeArrayBuilder& Call(
+      Register callable, Register receiver_args, size_t receiver_arg_count,
+      int feedback_slot, TailCallMode tail_call_mode = TailCallMode::kDisallow);
+
+  BytecodeArrayBuilder& TailCall(Register callable, Register receiver_args,
+                                 size_t receiver_arg_count, int feedback_slot) {
+    return Call(callable, receiver_args, receiver_arg_count, feedback_slot,
+                TailCallMode::kAllow);
+  }
 
   // Call the new operator. The accumulator holds the |new_target|.
   // The |constructor| is in a register followed by |arg_count|
   // consecutive arguments starting at |first_arg| for the constuctor
   // invocation.
   BytecodeArrayBuilder& New(Register constructor, Register first_arg,
                             size_t arg_count);
 
   // Call the runtime function with |function_id|. The first argument should be
   // in |first_arg| and all subsequent arguments should be in registers
@@ skipping 235 matching lines @@
   size_t offset_;
 
   friend class BytecodeArrayBuilder;
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_