Betrayed by a bitfield

Any chance you could file a bug on this one? It is not so bad if the non-standard use of volatile has this effect (although no doubt still very annoying to the kernel developers), but it seems to me to be something else when the code happens to be POSIX-conforming code and corrupts memory locations.

(Yes I have seen the argument in papers in the early proposals for the C/C++ threading model that "memory location" is ambiguous in Base Definitions, section 4.11, of the SUS, and could refer to a machine's natural word size rather than individual scalars, and so C11/C++11 now explicitly states that "memory location" in its equivalent wording means any scalar or bitfield, but that is a completely perverse construction of the SUS as it makes POSIX threads completely useless as a standard, bringing threading back to individual non-standard ABIs.)