[llvm] Treat ';' and '\n' as assembly instruction separators in collectAsmInstrs (PR #149365)

[Fangrui Song via llvm-commits]

https://github.com/MaskRay requested changes to this pull request.

This would break Mach-O, which uses `;` as a comment marker.

See `CommentString = ";";` in MCAsmInfo.cpp files. Unfortunately, IR cannot depend on MC..

https://github.com/llvm/llvm-project/pull/149365