Issue is created due to this request.

Issue

#I9MTXB:[新需求]: main() should not be always required - top-level statements are valid entry point

Description

This is a complementary patch in order to update a cts-test for an etsfrontend issue.

In case of a missing main() function in entry point source, an empty bodied main() is generated.

Test scenarios

• created some new runtime tests to test new cases and the order of running: test/runtime/ets/entrypoint*.ets
  • expected files of parser tests without main functions has to be updated.
  • and an expected file of an interop test so that it contains the generated main()

Reason

To meet the requirements of the language specs (13.8)

Fix #15343 internal issue.

Change-Id: Ibbfd4362b6b57992e2a59fcd6ecc192d3b0c9cf5