[clang] [clang-tools-extra] [llvm] [clang] Fix false positive -Wmissing-field-initializer for anonymous unions (PR #70829)

[Mariya Podchishchaeva via cfe-commits]

Fznamznon wrote:

@mikaelholmen , I see. I'll revert both patches to unblock you and I'll think about the proper solution after the holidays.
Perhaps there should be wider discussion whether we should emulate GCC behavior regarding silencing of these warnings.
IMO, the warnings you're seeing are correct, there is no initializer for field `b`. It is emulating of possible gcc bug that this patch breaks.


https://github.com/llvm/llvm-project/pull/70829