[llvm] OrcV2: also set COFF flag overrides when custom linking layer is used (PR #129533)

[Lang Hames via llvm-commits]

lhames wrote:

> Great, thank you. Let's use this version then instead of adding bindings of those methods.
> 
> Regarding the workaround: this is making a number of LLVM versions unusable for my project on Windows, so I was just wondering if you see some other way to set those flags that doesn't need changes in LLVM itself. (Maybe by creating a default linking layer and then retroactively applying the customization from the custom link layer) But I'm assuming it's not possible with the C API.

I think the LLVM change is the right way to go for now.

> Also: If/when `RTDyldObjectLinkingLayer` is deprecated, what will happen to C-API functions like `LLVMOrcCreateRTDyldObjectLinkingLayerWithSectionMemoryManager` or `LLVMOrcCreateRTDyldObjectLinkingLayerWithMCJITMemoryManagerLikeCallbacks`? Do you plan to adapt these bindings the `RTDyldObjectLinkingLayer` replacement, or will there be a new set of APIs?

They will also be deprecated.

There is no C API replacement for these yet. We'll need to implement new APIs for this.

What customizations are you using? Do you need to control layout, or just find out where particular sections / symbols are?

https://github.com/llvm/llvm-project/pull/129533