[libcxx-commits] [libcxx] [libc++] First attempt to regroup a few modules in the modulemap (PR #98214)

[Richard Smith via libcxx-commits]

zygoloid wrote:

It's possible that `#undef`ing only works with local submodule visibility enabled, but it does work -- if module A exports a macro, and module B imports A and undefs the macro, then importing both in either order results in the macro not being visible.  See https://clang.llvm.org/docs/Modules.html#macros for the details (this is also the model that we merged into C++20 header units).

https://github.com/llvm/llvm-project/pull/98214