[llvm] [ARM] [Windows] Use IMAGE_SYM_CLASS_STATIC for private functions (PR #101828)

[Martin Storsjö via llvm-commits]

mstorsjo wrote:

We could also add similar checking as was done in 1e7f592a890aad860605cf5220530b3744e107ba, to error out instead of creating relocations with a nonzero offset - I have such a change as well, which can be submitted as a separate step afterwards. I tried to keep this one as small as possible to reduce the risk wrt backporting it.

https://github.com/llvm/llvm-project/pull/101828