[Bug libstdc++/106042] std::__once_call abi unmatch for clang and gcc on windows targets

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106042

--- Comment #1 from cqwrteur <unlvsur at live dot com> ---
https://godbolt.org/z/bfeq935b6

https://godbolt.org/z/MjKsTPPfP

clang has exactly the same behavior for x86_64-windows-gnu and
x86_64-windows-msvc (only name mangling is different.) However
x86_64-windows-gnu indicates the abi defined by GCC, clang should match the
behavior of GCC or not the way around? Or GCC should match the behavior with
msvc? but they do not use the same thread model.