[libcxx-commits] [clang] [libcxx] [libc++] Rename `__` prefix to `__libcpp_` for locale related functions (PR #119241)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Which identifiers exactly are causing issues? I think we could tackle that by adding them to `__undef_macros` and to `_LIBCPP_PUSH_MACROS` and `_LIBCPP_POP_MACROS` instead. That's generally what we do to work around name collisions on individual platforms: it's more robust and doesn't require changing libc++'s source code due to name conflicts, which could be arbitrary (in principle, a platform could also be defining `__libcpp_strtof`, so the only bulletproof way of addressing this issue is push/pop).

https://github.com/llvm/llvm-project/pull/119241