[llvm] [ThinLTO] Don't mark calloc function dead (PR #72673)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay approved this pull request.

There are some comments from @cachemeifyoucan that should be addressed. You can use `lld/test/ELF/lto/libcall-archive-calloc.ll` to simplify the test.

https://github.com/llvm/llvm-project/pull/72673