Fix the bug that generates multiple definition of references

If a type ID is persent in local_to_global_type_id_map,
ModuleMerger functions should report that was_newly_added_ = false.

Test: ./test.py ; update prebuilts/clang-tools and build
Bug: 255702405
Change-Id: I0fbe68ebbc6b8df3ea4ae36a017d0bb61bc7d553
3 files changed