[clang] [llvm] [CodeGen][COFF] Always emit CodeView compiler info when hotpatch option is enabled (PR #142970)

[Jacek Caban via llvm-commits]

cjacek wrote:

I think we could emit this unconditionally, but I wasn’t entirely sure, so I went with a less invasive change for now. I'll prepare a new version.

In this version, Clang emits a full debug IR, but if we're going to do this by default, it probably makes more sense to emit just a minimal `llvm.dbg.cu` when debug info isn’t otherwise enabled. I’ve already experimented with that approach.

Also, enabling `/HOTPATCH` by default on x64 is an interesting idea. If we decide to go that route, then always emitting the compiler info (without conditioning) makes even more sense.

https://github.com/llvm/llvm-project/pull/142970