[clang] [lld] [llvm] [Windows] Add support for emitting PGO/LTO magic strings in the Windows PE debug directory (PR #114260)

[Martin Storsjö via cfe-commits]

mstorsjo wrote:

FWIW, no further objections from me on this one, but others may want to have another look (potentially also CC @MaskRay for the clang tests).

https://github.com/llvm/llvm-project/pull/114260