[libcxx-commits] [libcxx] [libc++] Make once_flag pointer-sized on MinGW (PR #219895)

[Martin Storsjö via libcxx-commits]

mstorsjo wrote:

Referencing https://github.com/llvm/llvm-project/pull/218924#issuecomment-5446066492 where this was discussed; this is known to be an ABI break, with a known non-zero impact, but we think the effect of it is acceptable here, as it fixes something which seems like a clearly unintended ABI setup (aka ABI bug).

https://github.com/llvm/llvm-project/pull/219895