[lld] [LLD] [COFF] Fix linking directly against an ARM64X DLL without import library (PR #210311)

[Martin Storsjö via llvm-commits]

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

LGTM!

(I also did a minor wording tweak to the PR description, I hope that's ok.)

https://github.com/llvm/llvm-project/pull/210311