[llvm] [gold] Use ld.bfd for tests (PR #130981)

[Nikita Popov via llvm-commits]

nikic wrote:

> For the cases that are not supported by ld.bfd (e.g. --start-lib), what should be the longer term plan? Do we want to delete these tests, or should an issue be opened with ld.bfd to support them?

Actually, ld.bfd already supports `--section-ordering-file` since 2.43 and `--start-lib` since 2.47. I can switch the tests to use those with a version check. I'll do that in a followup.

https://github.com/llvm/llvm-project/pull/130981