[lld] [LLD][COFF] Don't dllimport from static libraries (PR #134443)

[Martin Storsjö via llvm-commits]

https://github.com/mstorsjo commented:

I think this looks reasonable, thanks!

IIRC #109082 wasn't for a concrete issue after all (the case where we found this was messed up in other ways anywya), but I'd wait for @glandium to confirm that too.

https://github.com/llvm/llvm-project/pull/134443