[clang] [llvm] [llvm] minor fixes for clang-cl Windows DLL build (PR #144386)

[Andrew Rogers via llvm-commits]

andrurogerz wrote:

> I think that the clang semantics are technically correct

Yes,  agreed. And in case it wasn't clear, this is `clang` behavior and is not specific to `clang-cl`.

https://github.com/llvm/llvm-project/pull/144386