[clang] [Clang] Respect MS layout attributes during CUDA/HIP device compilation (PR #146620)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> This patch fixes an issue where Microsoft-specific layout attributes, such as __declspec(empty_bases), were ignored during CUDA/HIP device compilation on a Windows host. This caused a critical memory layout mismatch between host and device objects, breaking libraries that rely on these attributes for ABI compatibility.

Do we have to worry about ABI versioning for folks relying on Clang's current behavior?

https://github.com/llvm/llvm-project/pull/146620