[lld] [LLD][COFF] add __build_guid symbol. (PR #74652)

[Zequan Wu via llvm-commits]

ZequanWu wrote:

> I think we should go back to `__buildid`, I withdraw my suggestion for a more descriptive name. I'm just concerned someone will come along and tell us "this is not really a GUID", and then we'll look silly for using this name.

Renamed to `__buildid`. This still points to the 16 bytes hash after "RSDS".


https://github.com/llvm/llvm-project/pull/74652