[llvm] [LTO][Veclib] Fix vector library handling with LTO (PR #170638)

[Teresa Johnson via llvm-commits]

https://github.com/teresajohnson commented:

The changes seem straightforward, but it needs tests (probably in llvm/test/LTO/ARM?). Since you are modifying both the old and new LTO APIs, you'd want one using llvm-lto (old LTO API) and one using llvm-lto2 (new LTO API). As examples, there are some llvm-lto tests already in that directory, and some llvm-lto2 tests under the X86 directory.

https://github.com/llvm/llvm-project/pull/170638