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

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index 1c596503ef86e95bf3b6e3054ade3c484ae4a661..d4c3e81612d884705d1db2de78ade97e923bd2f6 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -3905,6 +3905,16 @@ Handle<Code> Builtins::CallBoundFunction(TailCallMode tail_call_mode) {
   return Handle<Code>::null();
 }
 
+Handle<Code> Builtins::InterpreterPushArgsAndCall(TailCallMode tail_call_mode) {
+  switch (tail_call_mode) {
+    case TailCallMode::kDisallow:
+      return InterpreterPushArgsAndCall();
+    case TailCallMode::kAllow:
+      return InterpreterPushArgsAndTailCall();
+  }
+  UNREACHABLE();
+  return Handle<Code>::null();
+}
 
 namespace {