[clang] [Clang] Allow simpler visibility annotations when targeting win32 and mingw (PR #133699)

[Hans Wennborg via cfe-commits]

zmodem wrote:

I too had trouble understanding this change based on the description. Could you give a concrete example of how mingw and msvc disagree on where to put the attribute, and explain how this pr changes things?

Taking a step back, how will this simplify libc++'s visibility annotations? Don't they still need to be compatible with both mingw and msvc, which we don't control?


https://github.com/llvm/llvm-project/pull/133699