[lld] [llvm] [llvm-dlltool] Fix renamed imports without a separate regular import entry (PR #98229)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

This goes on top of https://github.com/llvm/llvm-project/pull/98228, only the topmost commit is for review here.

https://github.com/llvm/llvm-project/pull/98229