[parser] Set allow_tailcalls in preparser

It does not really matter for the preparser
 but do it for sake of consistency.

BUG=

Change-Id: I2f58486cb3a8b866bbfa35b398abc7b5ead02ee7
Reviewed-on: https://chromium-review.googlesource.com/455797Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Wiktor Garbacz <wiktorg@google.com>
Cr-Commit-Position: refs/heads/master@{#43825}

src/parsing/parser.h

@@ -307,6 +307,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
                         parsing_on_main_thread_);
 #define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
       SET_ALLOW(natives);
+      SET_ALLOW(tailcalls);
       SET_ALLOW(harmony_do_expressions);
       SET_ALLOW(harmony_function_sent);
       SET_ALLOW(harmony_trailing_commas);