[lld] [LLD][COFF] Allow symbols with empty chunks to have no associated output section (PR #149523)

[Martin Storsjö via llvm-commits]

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

LGTM, thanks.

(It may be nice to mention "PDB" somewhere in the commit message too.)

Also for added context, this should be backported to 21.x, as this fixes a regression since f66f2fe0e5be6dc6eb3ef4d42af8692f9adcdc80 in one build configuration, as reported in https://github.com/mstorsjo/llvm-mingw/commit/ae0357758c2b3e93209fe89931b7f358def308e9#commitcomment-162336778.

https://github.com/llvm/llvm-project/pull/149523