[libcxx-commits] [clang] [libcxx] [clang] Add builtin to clear padding bytes (prework for P0528R3) (PR #75371)

[Eli Friedman via libcxx-commits]

efriedma-quic wrote:

If you want to modify part of a bitfield unit, you need to load/store the whole bitfield unit, as computed by the CGRecordLayout.  This is true whether you're modifying an actual field, or padding adjacent to a field.  Since any padding has to be adjacent to a bitfield, you can get the relevant information out of the CGBitFieldInfo for that bitfield.

https://github.com/llvm/llvm-project/pull/75371