[llvm-branch-commits] [clang] release/18.x: [clang codegen] Fix MS ABI detection of user-provided constructors. (#90151) (PR #90639)

[Reid Kleckner via llvm-branch-commits]

rnk wrote:

I should point out that it is an ABI break, but it aligns with MSVC, and the benefit of the fix outweighs the cost, so we should merge it.

https://github.com/llvm/llvm-project/pull/90639