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

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index 4ff7421536fe9f9b486bef21ebc131704fa36995..6539b9c0bbaf1ec740acca96584d54cd32c09562 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -164,8 +164,15 @@ class BytecodeArrayBuilder final : public ZoneObject, private RegisterMover {
   // |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|